Bad Little Boy is the 11th episode of Season 5 and the 115 of Adventure Time. It will air Febuary 18, 2013.
Fionna and Cake are riding on top of a giant Guntherina and chasing after Doctor Prince. Guntherina shoots a laser out of her mouth and it hits Doctor Prince and he drops the Enchiridion. Then he throws a Dolphin at them and they dodge it. The Dolphin turns around and says "Missed em" Then they jump off of him and say "Give us the Enchiridion!" Then he says "You want it? Take it!" Then he throws it to them but it's not a book it's a bomb. Fionna quickly throws it up in the air so it won't blow in her face and it explodes into cofetti in the sky. Then Doctor Prince pulls out the real Enchiridion and the Ice King comes out and slaps him on the face talking about what a nut job he is. Then Doctor Prince understands and jet packs away off into Nowheresville. Then Fionna and Cake congragulate him for it and he shares some lasagnia with them. Then they fly away into outer space on Cake's back and then Slime Princess interupts the story and says she want's to hear no more. Turtle Princess, Wildberry Princess, and Toast Princess agree with her and want it to stop but he ignores them. Then he starts flyng aroung and going nuts and it turns out that was Marceline using her invisibility powers to move everything around. Then she sets the Princesses free and tells her story which has Marshall Lee in it because that's the Gender-Swap of her. Marceline tells her story. It starts where Fionna throws a cutter at the tree dome wall and it cuts in half an apple on BMA's head and she gives the thumbs up signal to her. Then she throws another one and it cuts in half Gumball's hair on his head and they freak out but he puts it back together with his tounge and his spit and gives his gum puffs. Then A Big Swoosh slips em' off. Then Gumball forces Fionna to slave away lugging him and Cake and a bunch of other heavy stuff straight up a 90 degree angle up the height of the house in the rain just to get to the tippy top. At the top is Marshall Lee who welcomes Fionna but repels Gumball and makes him go downstairs to wait for Fionna and Cake to come back after their done talking to that stupid jerk. They ditch Gumball. They go to Lumpy SPace Prince's party that he's throwing cuz he hired Marshall Lee to sing a tune at his party. He sings a song at the party and Fionna does it with him. Then he gets annoying and hurts them both. Then he takes Cake and kidnaps her and Fionna has to battle some skeletons and get her back. The Marshall Lee is getting hurt in the sun. Then Fionna says that she does not have a crush on him and beats him up. She finishes up the story and everybody loves it better than the Ice Kings. Then they all leave.
- Prince Gumball's interaction with Marshall Lee has a similarity with Princess Bubblegum and Marceline's.
- This is the first episode without Finn and Jake.