Sora and Riku discover Julius while in Traverse Town's Fountain Square, where he jumps out of a sewer grate in the middle of the plaza and proceeds to attack them. Upon his defeat, Julius scrambles back under the sewer grate.
The hulking Julius resembles a fusion of the Frankenstein's monster and Pete, in both appearance and voice. He has red hair and wears a light blue shirt, dark blue pants and white gloves. He has only one leg while the other one has been replaced with a peg leg.
Julius is a powerful opponent. He possesses immense amounts of physical strength. Most of his attacks resemble wrestling moves, and are capable of easily felling Sora or Riku. Despite his large size, Julius is very agile, capable of running quickly and leaping great distances and heights. The monster is also capable of casting Thunder magic, utilizing it to electrify his fists, increasing his attack damage.
Julius first appeared in the animated short film Runaway Brain. He is the monster of mad scientist Dr. Frankenollie, who Mickey Mouse applied to work for "a mindless day's work" in order to pay for a trip to Hawaii that he and Minnie Mouse were taking. Frankenollie decides to perform an experiment which successfully switches Mickey's brain with the brain of his monster, leaving the two swapped in each other's bodies, though at the cost of Frankenollie's life. In Mickey's body, Julius finds himself infatuated with Minnie and tries to kidnap her. However, Mickey, in the body of Julius, manages to stop him and reverse the brain swap once more. Now back in his own body, Mickey manages to incarcerate Julius by trapping him in rope leaving him being pulled up and down like a yo-yo off of a skyscraper's billboard. In the end, Mickey and Minnie use Julius as transportation to get them to Hawaii by boat, comically by hanging a photo of Minnie in front of him to make him try to swim and reach the photo, unwillingly rowing the boat.