Julius

Julius is a giant hulking Frankenstein-like version of Pete that was created by Doctor Frankenollie. A monster (of fairly low intelligence) who hosts Mickey's brain for a short time. He has been identified by some as Peg Leg Pete, because of the physical similarities and the missing leg on his left foot.

Runaway Brain
Julius is unleashed from his lair under Frankenollie's lab to switch brains with Mickey Mouse. The experiment was done successfully although it killed Frankenollie in the process. However, Julius and Mickey not only switched brains, but bodies as well. In Mickey's body, Julius was able to view Mickey's wallet where he finds a picture of Mickey and Minnie. He develops feelings for her and rushes out to find her. He spots her at a shopping store and enters to proclaim his love. Unfortunately, Minnie thinks it's Mickey she's talking to and when the real Mickey in Julius' body enters to save her, she attacks him. Mickey is able to explain and battles Julius while Minnie is safe on top of a skyscraper. Mickey and Julius end up being electrocuted on cable wires, switching back in the process. Now that Julius is in his rightful body, he has a better chance of destroying Mickey and getting Minnie. Still, Mickey manages to free Minnie from his grasp. He is accidentally knocked off the building by Minnie but is pulled up repeatedly like a yo-yo as he is tied to a rope attached to a moving Hawaiian girl's arm on a billboard. In the end, Mickey and Minnie use Julius to pull a raft to Hawaii for vacation.

Kingdom Hearts 3D: Dream Drop Distance
Julius appears as a secret boss in the game, located in Traverse Town. He emerges from a sewer grate below to the surface to attack Sora or Riku. After defeating him, he retreats back to the sewer grate and Sora or Riku earn the Ultima Weapon Keyblade. He's the first secret boss in the Kingdom Hearts series to be actually a Disney character (if one does not count fighting Ice Titan and the Earth Titan during Kingdom Hearts in Olympus Coliseum). Why he attacked the boys or how he wound up in Traverse Town is unknown.

Role in Ultima
In Ultima, Julius was revived by Maleficent to serve as a Juggernaut in the Organization's Army. Julius's outfit has been redesigned into a KH-version of his normal outfit. Because Julius has two forms of himself, Maleficent split him into two characters: Julius Pete and Julius Mouse.