Julius is the main antagonist of Disney's Runaway Brain. He is a monster resembling a hybrid of Frankenstein's Monster and Peg Leg Pete who ends up being in Mickey Mouse's body.
He was voiced by Jim Cummings.
Julius is the creation of Doctor Frankenollie, who wishes to unleash his creature on the world. To do this, Frankenollie places an ad on a newspaper with an exorbitant price to his place, which is noticed by Mickey Mouse. Mickey arrives in Frankenollie's, who promptly switches Mickey and Julius's brains. Though Frankenollie succeeds in this, he is killed in the process.
Julius finds a picture of Minnie in Mickey's wallet and develops feelings for her. He escapes the lab, spots her at a shopping store, and enters to proclaim his love. Minnie thinks it is Mickey she is talking to, and when the real Mickey in Julius's 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 brains 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.
Julius appears in Kingdom Hearts 3D: Dream Drop Distance as a secret boss. When Sora and Riku arrive at Traverse Town's Fountain Court, Julius emerges from a sewer grate in the middle of the arena and engages the Keyblade wielders in battle. After an arduous battle, Julius flees back into the sewers, leaving behind the Ultima Weapon Keychain.
Julius's fighting style borrows heavily from commercial wrestling, incorporating moves such as one-two punches, body slams, and a leaping crash. He can also grab Sora or Riku and belch on them, inflicting Blind, Confuse, and/or Poison. As his health dwindles, he can infuse his fists with electricity, temporarily boosting the range and power of his attacks. His leaping crash in this state, if it connects, can force Sora's or Riku's selected command to reset and double its load time (unless the command is an item). He periodically enters this state for the rest of the fight. If he is at his last bar of health when this happens, the effect is permanent until his defeat.
It is unknown why Julius is in Traverse Town in Kingdom Hearts 3D. However, in the cutscene prior to his battle, the sewer grate he rests in glows red, implying that he was sealed there.
Due to being a version of Pete, Julius is voiced by Jim Cummings in English and the late Toru Ohira in Japanese.
Julius is the first secret boss in the Kingdom Hearts series to be of an existing Disney character.