Body Trouble is the 3rd episode of season 2 of Uncle Grandpa, and the 55th episode overall of the series.
When Uncle Grandpa and Belly Bag have a disagreement, they separate and try to make each other jealous.
Uncle Grandpa asks Belly Bag what's today and Belly Bag said "Work on the side of a cliff day?", Uncle Grandpa laughs and corrects Belly Bag that today is Cake Day and Belly Bag gets real excited to bake a cake and wants to try out his perfect recipe. Belly Bag tells Uncle Grandpa to put two teaspoons of vanilla extract but Uncle Grandpa puts more than two teaspoons, Belly Bag tells Uncle Grandpa that is was way more than two and Uncle Grandpa says that it means more cake, back to the recipe, Belly Bag says to add two cups of flower but instead Uncle Grandpa puts in two sacks of flower. Belly Bag is getting mad that Uncle Grandpa is ignoring his instructions, Uncle Grandpa says that instructions are just suggestions and he adds pop to the cake, he tastes the cake and decides to add candy to the recipe, Belly Bag then says that there isn't candy in the recipe or peanut butter or raw meat, or sprinkles. After seeing sprinkles in the cake, Belly Bag thought it was appropriate until he saw the sprinkles coming from Uncle Grandpa's mustache and with the comb into the bowl, Belly Bag gets frustrated saying that Uncle Grandpa is ruining the cake, Uncle Grandpa says "Says Who?" and they both yell at each other until Belly Bag gets the suggestion for them to separate. They both separate an they both try to get each other mad, Belly Bag got mad and runs off to find a new head.
Belly Bag is talking to himself saying how any head would be an improvement than Uncle Grandpa, Belly Bag then sees the Zebra Head and gets the idea to use that for a new head. Belly Bag walks into the room with the Zebra Head and walks to the mirror to admire himself, Uncle Grandpa thinks than since Belly Bag can replace him, he should replace Belly Bag and he hops to a stool for his new body. Tiger stares at Belly Bag with the Zebra Head and Belly Bag questions why she's looking at him like that, Uncle Grandpa says that tigers eat zebras and Tiger chases Belly Bag into the pipe, and as Uncle Grandpa begins to walk out, the stool breaks. For Uncle Grandpa's next new body, he decides to use the cat clock and shows it off to Belly Bag but the clock body's alarm went off causing Uncle Grandpa to fall off. Belly Bag finds Uncle Grandpa's choice of bodies quite alarming, but his new head (Disco Ball) is going to be the life of the party but the disco ball won't stop spinning and Belly Bag tries to stop it from spinning but it spins him out of control. Uncle Grandpa notices Belly Bag's new toaster head and tells him that he found the best new body ever, a toy race car, and he zooms out of the room, the toaster head gets mad and blows up, in the arcade Uncle Grandpa meets with Pizza Steve and tells him about his new body but Pizza Steve has the remote control and makes Uncle Grandpa crash his new body. Uncle Grandpa searches for the perfect body by popping up from the oven and the grill, and then he tries on Frankenstein's body and he admires all of it's features, Uncle Grandpa then leaves the room to go show it off to Belly Bag. Belly Bag had found his new perfect head, a pickle, they both meet up and Belly Bag likes Uncle Grandpa's falling apart body and hopes that he can keep it together, and Uncle Grandpa tells him that he better hopes that he won't be getting back on his pickle only diet anytime soon.
Mr. Gus enters the RV with some groceries and both Uncle Grandpa and Belly Bag welcomes him with a HAPPY CAKE DAY!! First of all Mr. Gus wonders who parked the RV on the side of a cliff and they both raise their hands and he wonders what's up with both of their bodies. Mr. Gus wonders what happens when he goes out for groceries, Belly Bag tells him that him and Pickle Head baked a cake for cake day and tells him to try the cake, Mr. Gus says that the cake tastes bland, Uncle Grandpa then tells Mr. Gus to try out his cake and he says that it tastes like mustache. Since Mr. Gus picked Uncle Grandpa's cake as his favorite they decide to celebrate, Uncle Grandpa decides to dance and then Belly Bag decides to dance to make Uncle Grandpa jealous and they both decide to have a dance off, Belly Bag pushes Uncle Grandpa into the DJ table and they both continue to dance fight. They do the Dosey Do and they fly into the RV cockpit and they put the RV into reverse and the RV falls off the cliff, Uncle Grandpa and Belly Bag are against the windshield and they both apologize about Belly Bag thinking Uncle Grandpa can't bake a cake and Uncle Grandpa not following the instructions properly. Uncle both reconcile and they both decide to bake a cake together, while falling Belly Bag tells Uncle Grandpa what to drop out of the window to bake the cake and when the cake is done the RV falls safely on the ground. When it's night time everyone is eating cake and Mr. Gus tells Uncle Grandpa and Belly Bag that Cake Day is not a real day of the week, Uncle Grandpa is stunned and he tells Belly Bag why he didn't tell him Cake Day isn't a real day and they both start to argue again about Cake Day.
- It's unclear if Belly Bag can see without Uncle Grandpa's head since he walked straight into a lamp and Belly Bag was facing towards the lamp, although he baked a cake without Uncle Grandpa's help but he had a pickle for a head so that can mean he could have vision based on what ever head he possesses.
- Another theory could be that Belly Bag's eyes are the suspender buttons above him as they can be seen moving through out the episode.