Derrick McCormick's apartment has been infested with roaches and has nowhere to go! To solve this problem, he has this mysterious and weird dimension box that contains different dimensions. Taking his pet Tommy with him, he jumps inside the box. It has various places that he can go to, and he suddenly ends up in Capitol City. There he eventually meets Baby Lamb and all of his friends and they all get along very well. But little did Derrick know that an evil guy named Joshua is out to get him!
The crossover begins in the "Derrick McCormick" universe, inside Derrick's room, where he's busy singing the "Drake & Josh" theme song to fix his vocals. He introduces the audience and says he wants to join the chorus but his pet bird, Tommy, can't stand his singing. But Derrick doesn't care. He tells the viewers about how Tommy is both likable and annoying, right before Tommy hits on Derrick's head annoyingly like a woodpecker. Nevertheless, Derrick thinks today is gonna be a very special and perfect day.
Derrick admires the day today until he notices the Bunny Twins arguing over a bag of Cheetos. He gets their attention and says that they should just share the bag of Cheetos. Eventually, the Bunny Twins settled out their situation. Afterward, Derrick gets something to drink out of the fridge, but not before noticing a strange noise in the distance. So he checks on his phone and realizes there's an emergency, telling him to turn on the TV. He checks the news and finds that there's a horrible roach infestation at every single house in Middleton, and he's ordered to leave his apartment until roach season is over. Derrick is absolutely shocked and then frustrated. He realizes how serious this issue is but has no idea where to go. But he then gets an idea and mentions a dimension box that can take him into any dimension in the universe, but he hasn't used it since he was 12. Nevertheless, he has no other choice. But before he leaves, he decides to say goodbye to his apartment and reminisces the memories he's had there and then says goodbye to his friend, Lucky. So Derrick and Tommy prepare to jump inside the dimension box but Derrick was reluctant at first but he did it anyway and it takes him across the entire multiverse!
Derrick and Tommy suddenly end up in Capitol City, conveniently outside The House, where both of them are paper puppets. Suddenly there's a low rumbling and it turns out to be none other than Baby Lamb riding on top of his best friend, Cow, leaving Derrick in awe. But eventually, Baby Lamb and Cow accidentally bump into Derrick and Tommy. After they got back up, Baby Lamb and Cow introduce themselves to Derrick and Tommy and vice-versa, realizing that they all can get along. Derrick admires The House while Baby Lamb and Cow ask Derrick about his house, leading him to explain his situation with the roaches. Derrick asks if he can stay with them for a while and Baby Lamb was about to accept until Cow privately talks to him, being unsure about it since they only knew Derrick and Tommy for a couple of minutes. But Baby Lamb encourages him to be good neighbors and offer him a place to live. So they both let Derrick and Tommy stay at their house, and they give him the grand tour. They go inside the house, where Derrick is very amazed by what the room looks like, even mentioning how similar it is to his apartment back home. Derrick sees a picture of Baby Lamb with all his other friends, whom Baby Lamb talks about and will introduce to him eventually.
Baby Lamb, Cow, Derrick, and Tommy visit the Police Fort where Chief Mark appears to be arguing on the phone with Sir Topham Hatt until Baby Lamb gets his attention. Mark thought it was an emergency until Baby Lamb said he wanted to introduce him to Derrick and Tommy, but Mark was rather annoyed because he thought it was an emergency and told Baby Lamb firmly not to interrupt him unless there's an emergency. After that, the guys meet Cow's brother Calf and his friend Peep, both of which just came from daycare. Tommy interacts with them, immediately getting along with Calf and Peep, and eventually, the three decide to go to the park together. In the meantime, Baby Lamb and Cow introduce Derrick to the rest of their friends.
Ricky Bowers is shown wearing a fake mustache and delivering a news report, which turns out to be him admiring his appearance, while Donny Dolphin films. Baby Lamb and Cow show up, annoying Ricky because they interrupted his news report until it turned out that the camera Donny was using hasn't worked in years. Baby Lamb and Cow then introduce Derrick to Ricky and Donny and eventually he also meets Belle and Alice, admiring how adorable they are (much to Alice's disgust). After being asked what brings him here, Derrick explains his situation where Baby Lamb and Cow offered to let him stay and everyone else allows him to stay, liking him already. Soon after that, Calf, Peep, and Tommy return, and it turns out Tommy has become very popular with them. After Calf and Peep leave, Tommy asks Derrick if he told them that he came from another dimension, but he couldn't because they wouldn't believe them. But, knowing how he should be honest, he decides to tell them that he comes from another dimension. As expected, they don't believe him but Baby Lamb does because him coming from another dimension isn't the weirdest thing that has happened, leading the gang to bring up some supernatural events from previous episodes. Donny asks Derrick how he got here from another dimension, so Derrick explains that he used a dimension box. Intrigued, Donny brings out a book that explains what a dimension box is and warns that the consequences of traveling to dimensions could be VERY devastating. It turns out that Donny has a dimension box of his own, only it's much different-looking compared to Derrick's box. Derrick began to miss Middleton and the people he knew there, but Baby Lamb assured him that maybe roach season will be over. Only Belle wonders how he's gonna get back. Donny thinks that Derrick can use Donny's dimension box to get back. Feeling overwhelmed, Derrick leaves to think about this.
Walking into Town Square, Derrick overhears Bill and Mejax fighting over a bag of Cheez-its. Mirroring the earlier situation with the Bunny Twins arguing over a bag of Cheetos, Derrick encourages Bill and Mejax to share the Cheez-its and eventually they decide to do so, thanking Derrick for the help. Derrick and Tommy decide to take a vacation in Capitol City until the roach season is over. Baby Lamb comes up to Derrick and asks if he's alright. Derrick is surprised by Baby Lamb's kind nature, but Baby Lamb says he wants to help out his friends, even new ones. The two have a wholesome moment as they compare each other's dimensions and realize that they have a lot in common, and Derrick is very appreciative of Baby Lamb and his friends' kindness and welcoming demeanor when he first came here. Darryl the Dragon shows up, and while Derrick is shocked at first, he finds out that Darryl is nice (and also enjoys making puns about fire). Baby Lamb and Derrick see that this is the beginning of a wonderful friendship, and the two go out to have some fun. Derrick talks to Tommy and says he was right when he said it was a special day.
"But What is It Segment?" as Derrick and Simon describe what is and what isn't a collab.
Derrick shows Cow how to play "The Throwing Game" where he has to throw any random object he sees, and so he throws Ricky. Baby Lamb and Belle play "Flashlight Tag", which is what Derrick also taught them to play. Meanwhile, Donny asks Tommy what it's like being a bird and takes notes as Tommy speaks. Suddenly Derrick gets an email on his phone which is from his landlord, saying that roach season is over and all the roaches in Middleton have been taken care of, thankfully. However he has to pay $400 in rent money by July 3rd or else he won't be able to live in his apartment anymore. The problem is Derrick doesn't have that money and July 3rd isn't very far, but Derrick is certain that his landlord is a very nice guy.
The scene cuts to Middleton, where an evil guy named Joshua is shown to have been the one who sent the email and now can use the rent money on whatever he wants.
Back in Capitol City, Derrick is looking for ideas to earn money to afford his rent. Cow suggests he should get some money....which doesn't prove to be any help. Baby Lamb says that maybe his friend, The Count Von Count, can give him some money but Belle reminds him that The Count only uses the money to count. Ricky came up with an idea and suggests that Derrick starts a clothing line based on what he's already wearing. Derrick explained that his parents gave him his clothes. Belle asks why he couldn't live with them after he got evicted, and Derrick explained to them that his parents were killed when he was very young and he doesn't know who killed them. He lived with his grandparents after that and they gave him his own apartment so he can be more independent. Alice suggested that he tracks down whoever killed his parents so he can kill him back and Derrick agrees, but Baby Lamb says vengeance is never the solution because it would make him the killer as well and it wouldn't be worth it in the end. Derrick understood. Donny thinks that maybe Derrick should just simply get a job, but Derrick thinks it's weird since he planned on staying in Capitol City for vacation. Belle and Baby Lamb are positive that Derrick himself will think of something, and that his landlord is a very nice and understanding person.
Back in Middleton, Joshua thinks that sending that email wasn't enough and wants to do something to get rid of Derrick once and for all and actually kill him! He gets into Derrick's room and finds his dimension box, leading him to travel to Capitol City. It turns out that he hated Capitol City and everyone in there. For a brief moment, he stumbles into a bunch of balloons, which were from Uncle Lamb as he's running a balloon business. He finds Derrick and Baby Lamb and his friends and realizes that he's outnumbered and taking Derrick down isn't so easy, making him wish for something that can get him a group of people. Suddenly, a sneaky person named Maxwell Snark walks up to Joshua and offers to give him a mind-control device, which looks like a TV remote but Maxwell ensures him that it'll work after a mild demonstration. However it's going to cost him $400 (coincidentally the same amount of money Derrick needs to pay for rent). Joshua leaves without paying anyways and tricks Maxwell. Wielding the device, Joshua finds Darryl, Bomb, Terence, Gus Grizzly, and Roger Rex, making them the perfect candidates for his army. He begins to use the remote to mind-control them.
Meanwhile, the gang and Derrick and Tommy were watching an episode of Mister Rogers' Neighborhood, which Derrick remembers and Baby Lamb admires greatly. He mentions how Mister Rogers taught him that the real friends will never turn against you for any reason at all until Darryl the Dragon snuck up to Baby Lamb and roars at him. Eventually, Darryl started shooting fire breath and attacking everyone, leaving both Derrick and Baby Lamb surprised because usually, Darryl is very nice. Then things get worse from there when Bomb launches into the gang, causing an explosion and flying Cow into the Police Fort, where he gets attacked by Gus. Darryl captures Donny, Bomb captures Baby Lamb and Belle, Roger attacks Alice, and Ricky gets attacked and then captured by Terence. Joshua was responsible for mind controlling them to attack Baby Lamb and the gang, where he sets off to take down Derrick himself while holding a knife.
Derrick and Tommy realize how intense the situation is until Joshua gets Derrick's attention and almost kills him until Derrick runs away, leaving Joshua to hunt him down. Derrick and Tommy realize they can't stop Joshua and save the gang by themselves, so they call everyone from "ICup's Universe" to come and save them. ICup and his friends travel to Capitol City from their universe to help Derrick and save Baby Lamb and his friends. The gang finds themselves cornered with everyone that Joshua mind-controlled about to kill them until the Neighborhood Trolley comes with ICup and his friends inside to save the day. Cow thinks Trolley became evil, too, until ICup explains that they're on the Lamb gang's side. After introducing each other, the gang explains what happened. They think it has something to do with that remote control which Joshua used to mind-control some of the Capitol City citizens. Baby Lamb doesn't believe it until Donny tests it out and everyone that attacked Baby Lamb and the gang were suddenly reverted back to normal, not realizing that they tried to kill them. Belle is just concerned right now what's going to happen to Derrick.
Hoping that everyone is ok, Derrick thinks that the coast is clear until suddenly he gets caught by Joshua with a knife to his neck. Tommy hurries off to tell Baby Lamb what happened and he explains it to everyone else that some crazy lunatic is trying to kill Derrick. ICup is shocked so everyone decides to band together and save Derrick. Joshua, holding his knife up against Derrick's chest, tells Derrick that he's the one who sent him that email about the rent money and reveals himself to be his landlord. Derrick wants to know why Joshua hates him so much, and it's because he's so well-loved and admired despite the fact he doesn't even earn money. But Joshua thinks that once Derrick is out of the picture, he'll get the fame and recognition he craves. Before long, however, he finds himself surrounded by Baby Lamb, ICup, and everyone else. Cow shows Joshua that they found out about the mind-control device, so he decides to throw it in the trash. Joshua is disgusted but was about to kill Derrick with the knife until Belle took it out of his hands, and ended up cutting Joshua himself. Now Joshua was really angry and was about to kill Belle as well with the knife until Baby Lamb jumped on top of Joshua and tackled him. Then he ran up to Belle, hoping she's alright and she kissed Baby Lamb. Joshua then decides to kill Baby Lamb as well until he got interrupted by someone that he feared would come: a very tall old man named Mr. Landlord, who appears to know Joshua personally.
Joshua thought Mr. Landlord was supposed to be on vacation until it turns out that he's been vacationing in Capitol City with his son but was surprised to find Joshua, especially when he was about to murder 2 children. Mr. Landlord finds Derrick McCormick and introduces himself to him, and then explains that Joshua was temporarily filling in for Mr. Landlord while he was on vacation. It's revealed that Mr. Landlord owned Derrick's apartment since he was a child and when Derrick brought up the $400 rent money, Mr. Landlord was surprised at how much Joshua forced him to pay and found out he was gonna use it to buy drugs and alcohol. Joshua had no choice but to explain the full story. He originally came from a rich family and lived a privileged life with a future planned out. He wanted to be a doctor but throughout his life, the only thing that made him happy was nothing more than money. It caused him to have a lack of friends, failure to complete medical school, and his whole entire life went down the toilet to the point where he lost everything. He became a landlord because he and Mr. Landlord were friends for a while and he was aware of Joshua's financial struggles so he wanted to help him out until he realized what a toxic person he became. It turns out that he hated both Baby Lamb and Derrick for how likable, well-known, and beloved they were even though neither of them made money on what they did. Derrick explained that he cares about a lot of things except for money because it can never buy friendship and happiness. Mr. Landlord decided to evict Joshua permanently and strip him from his landlord title. This filled Joshua with so much rage that he prepares to kill them with his knife until he gets run over by the Neighborhood Trolley, which appeared to have been driven by Calf and Peep. Derrick asks if Mr. Landlord was gonna return to Middleton and become the landlord, which he is only he's planning on retiring from being the landlord and decides to make his son, Brendan (a friend of Derrick's), the landlord instead because he feels that he'll be a lot more responsible than Joshua. Derrick only wonders what's gonna be done about Joshua until Donny gets an idea.
Donny gets an idea and so Joshua is sent to someone's bathroom until he hears someone's voice. It turns out that he was sent to the SuperMarioLogan dimension and he ends up inside the bathroom with Shrek as Shrek unloads a lot of crap to Joshua's expense. After musically celebrating the fact that everyone stopped Joshua and saved the day, Derrick and Tommy decide to head back home.
Everyone gathers together at Donny's dimension box to say goodbye. Derrick shows his appreciation to Baby Lamb and his friends for caring about him, helping him out, and being very nice, kind, and welcoming. Baby Lamb says that's what friends are for and friends will always be there for each other no matter what, even if they're different. Derrick agrees and Baby Lamb and his friends show that there are still good people in this world and that the bad in this world will never matter. Cow is very touched that he begins to cry as Donny comforts him. Baby Lamb's friends say goodbye to ICUP's friends while Baby Lamb and Derrick personally say goodbye to one another. Derrick says that Baby Lamb has a big heart for a little lamb and is similar to Mister Rogers. Baby Lamb is beyond flattered and says that Derrick's parents would be very proud of the person he's become, leaving Derrick choked-up with emotion. The two share a hug. After that, Derrick says that Baby Lamb and Belle make a cute couple, as the two laughs for a bit. Everyone says their final goodbyes as Derrick and his friends head back into their dimension.
Baby Lamb misses them already while Donny plans to get rid of the dimension box. Shocked, Baby Lamb wonders why until Donny explains that while he sympathizes with his feelings, traveling across dimensions is dangerous and the fabric of the multiverse should not be messed with. He won't destroy it but he'll put it in a place where nobody can find it unless there's a situation where it may be needed again. Baby Lamb wonders if he'll ever see Derrick again. Cow thinks maybe he'll make videos of his dimension and post them on YouTube. Baby Lamb doubts that but then figures that there will always be a way to be connected with him.
"What Can You Do Segment?" Simon A. is looking for something to wear while he goes out and then decides to wear a fancy sequined gold tuxedo....only it turns out he was just heading to the supermarket.
In an epilogue scene, Baby Lamb is busy making something until Belle sees him and wonders what he's doing. Baby Lamb explains that he's making a present to surprise Derrick because he feels bad that he has to deal with toxic people despite being very kind and helpful to so many people. Baby Lamb wants to give Derrick a gift as a way to remind him that even if they live in different dimensions, he will always think of him and care. He asks if Belle wanted to deliver it with him, and she happily agrees but remembered that Donny got rid of the dimension box. Baby Lamb revealed that Donny hid it under the bed the whole time, thinking that Baby Lamb wasn't going to look there. So, the pair decide to head to Middleton to give Derrick a surprise present.
Derrick and Tommy are back home in Middleton, and Derrick looks back on the crazy adventure he had meeting Baby Lamb and his friends and the experience of being a paper puppet in Capitol City. It goes to show that there will always be good people in the world. Derrick can't stop thinking about Capitol City. He talks to Imaginary Man about his time in Capitol City and about how great and kind Baby Lamb and his friends are. Imaginary Man said that he saw a butterfly and a lamb come into Derrick's room to send him something. Realizing that Imaginary Man referred to Belle and Baby Lamb, Derrick finds Baby Lamb's present for him on the bed and is very touched and amazed. He says "peace out" to the viewers, saying that cannot stop looking at the present. The crossover ends as Baby Lamb's present to Derrick is shown to be a drawing of all the characters from Derrick McCormick and Baby Lamb & Friends together with a message saying "To Derrick McCormick. You will always be our friend".
As the credits roll, Simon A. and Derrick McCormick sing a cover of the song "On the Open Road" from A Goofy Movie.
- Derrick McCormick (played by Derrick McCormick)
- Baby Lamb (voiced by Simon A.)
- Cow McMoo (voiced by Simon A.)
- Belle Butterfly (voiced by Cami J. Green)
- Alice Pennington (voiced by Marisa the Gem Fox)
- Ricky Bowers (voiced by Simon A.)
- Donny Dolphin (voiced by Simon A.)
- Joshua (voiced by Derrick McCormick)
- ICup (voiced by Derrick McCormick)
- Carson (voiced by Derrick McCormick)
- StarStruck (voiced by Jaylynn Russell)
- Bow-Wow (voiced by Derrick McCormick)
- Ball (voiced by Derrick McCormick)
- Brownie (voiced by Jaylynn Russell)
- Maxwell Snark (voiced by Simon A.)
- Darryl the Dragon (voiced by Simon A.)
- Gus Grizzly (voiced by Simon A.)
- Roger Rex (voiced by Simon A.)
- Calf McMoo (voiced by Simon A.)
- Chief Mark (voiced by Simon A.)
- Bill Quackers (voiced by Simon A.)
- Mejax Webster (voiced by Simon A.)
- Mr. Landlord (voiced by Derrick McCormick)
- Brendan Landlord (voiced by Derrick McCormick)
- Neighborhood Trolley
- Uncle Lamb (voiced by Simon A.)
- Bunny Twins (voiced by Derrick McCormick)
- Imaginary Man (voiced by Derrick McCormick)
- Mickey Mouse (cameo)
- Minnie Mouse (cameo)
- This is the first official crossover involving Baby Lamb & Friends.
- References to previous episodes of both Baby Lamb & Friends and Derrick McCormick are made in this episode.
- Baby Lamb and the gang referenced moments from "Baby Lamb & Friends: The Movie", "April Foolin' Around", "Dave the Alien", "Curse of the Were-Lamb!", and "The Lucked-up St. Paddy's Day", when they brought up supernatural events that previously happened.
- Belle referenced the episode "Gift of the Fools" when she mentioned how The Count only uses his money to count.
- Despite some of the posters promoting the crossover featuring Alice in her original caterpillar design, the crossover features Alice in her new redesigned fly form, the first official Baby Lamb & Friends production featuring Alice's new design.
- In spite of this, Derrick referred to her as a caterpillar at one point in the crossover.
- Chronologically, the crossover takes place after the events of I Can Make a Change: Part 2 which introduces Alice in her new fly redesign.
- ERROR: Alice's fly wings are missing throughout the majority of the crossover and only appeared after Derrick and Baby Lamb sang "Capitol City is Back". It turns out that Simon A. forgot to draw wings for the paper puppet of Alice but didn't want to reshoot everything because it was already too late.
- It was originally planned to be a 45-minute special but it eventually stood at an hour and 28 minutes long, making this the second-longest Baby Lamb & Friends-related production (the first being Baby Lamb & Friends: The Movie).
- As a result of the crossover's extended runtime, Simon A. has confirmed that this is the sequel to Baby Lamb & Friends: The Movie.
- This is also the final Derrick McCormick special made for Era 2 (which has lasted from April 2, 2017, to July 1, 2020).
- BEHIND THE SCENES: 25 minutes of the episode were originally edited with the MacBook Air Simon A. used to produce Baby Lamb & Friends episode since 2017 but it, unfortunately, crashed midway through editing so Simon ended up editing the entire crossover with a brand-new 2020 MacBook Air which will be used for future episodes (and Baby Lamb Creations videos in general).
- This is Derrick McCormick's second involvement in a Baby Lamb & Friends production, the first being his appearance as his character of the same name in the movie's cold opening scene.
- This is Simon A.'s third involvement in an UNODASH !!! production.
- The first was his guest-starring appearance in the Derrick McCormick episode "Whodunnit?" and also the episode "The Bovine of Seville" appearing in the Derrick McCormick Season 3 finale "A Bunch of Shorts".
- Interestingly, Cami J. Green (the voice of Belle) also appeared in the latter.
- The first was his guest-starring appearance in the Derrick McCormick episode "Whodunnit?" and also the episode "The Bovine of Seville" appearing in the Derrick McCormick Season 3 finale "A Bunch of Shorts".
- This is the first official Baby Lamb Creations and UNODASH !!! collaboration.
- This is the first time that Baby Lamb and Belle actually kiss.
- There were a few deleted scenes that didn't make the final cut for this movie (mostly due to foul language):
- After Alice suggested Derrick to track down the killer of his parents, Derrick said "I'd f*cking make him pay." Although it was improvised by Derrick when dubbing his lines, it had to be removed on account of how Simon A. never allows full use of the F-bomb in Baby Lamb & Friends.
- When Belle accidentally cuts Joshua with the knife, there was originally a scene where Ricky said "Wow, Belle! I had no idea you were such a badass."
- Derrick was singing the theme song to Drake & Josh at the beginning.
- Baby Lamb mentions Mister Rogers when he encourages Cow to be a good neighbor. Later on, Baby Lamb, Derrick, and the rest are shown watching an episode of Mister Rogers' Neighborhood.
- Bill invites Mejax to watch the movie Shrek with him while they eat from a bag of Cheez-its.
- Joshua insultingly calls Maxwell Snark "Inspector Gadget".
- Joshua references the famous "I am your father" scene from Star Wars when he reveals to Derrick that he's his landlord.
- Baby Lamb mentioned Bugs Bunny and Daffy Duck after Ball is surprised that they're gonna brush it off after getting killed.
- Shortly before throwing the mind-control device in the trash, Cow shouted "Kobe!". This is a reference (and also a brief tribute) to the late NBA basketball icon, Kobe Bryant, who was sadly killed in a helicopter crash in early 2020.
- After Belle cuts Joshua by mistake with the knife, Joshua was about to say "You son of a b*tch" until Simon A. interrupts with a "Viewer Mail Time" segment, referencing that from Back at the Barnyard which eventually became a popular meme.
- Shortly before getting his comeuppance, Joshua said "I would've gotten away with it, too, if it weren't for you meddling kids and that stupid lamb!". This references a well-known line commonly said in the Scooby-Doo franchise whenever the antagonist gets unmasked and eventually arrested.