Jack Spicer

Jack Spicer is a self-proclaimed "Evil Boy Genius" and one of the main villains. He is constantly building different types of robots, the most common of which is the Jack-Bot. His first appearance was in "The Journey of a Thousand Miles" where he met the Heylin witch Wuya and learned of the mystical Shen Gong Wu. He says that he has wanted to rule the world since second grade. As mentioned above, Jack is an experienced robotic engineer, and he is not above sobbing in public or screaming in terror. Jack also gets minor nose bleeds when exposed to great hights rapidly.

Jack lives in his parents' basement, which he uses as his secret lab. His parents are never seen, nor were they mentioned that much in the series. However, it has been shown that his parents (or his father at least) appear to be involved in some high position or profession, as they appear to be relatively wealthy. He also has a blond cousin Megan, who is much younger than he and is aligned with the Xiaolin.

Examples of Jack's "evil heroes" are Chase Young and Hannibal Roy Bean. He looks up to those evil heroes and tries to form partnerships with them, usually ending up with him getting hurt.

At times, he has gone into the Ying-Yang World, losing his evil side and coming out as a "good Jack," who is quirky, spunky, dramatic, and what can only be described as the ultimate good. After this happened in "Saving Omi," Good Jack went back into the Ying-Yang World. He then used the Ring of the Nine Dragons to duplicate himself, and only one of these clones left. Because this clone only used the Yang Yo-Yo to leave, he regained his evil chi, essentially going back to normal Jack. Good Jack appeared again in the episode "The Life and Times of Hannibal Roy Bean" when regular Jack found the prison that held Hannibal Roy Bean. Hannibal tricked not Jack, but the monks, into letting him out by using the Moby Morpher to turn into Jack. Hannibal (still in disguise) wasn't found out until the monks ran into regular Jack as well as Good Jack. In order to identify the fake, they used the Ring of the Nine Dragons to reunite the two correct Jacks.

Later in the episode "Hannibal's Revenge" Kimiko disguises herself into looking like Jack in order to win a showdown. In the last episode Jack is left with his favorite Shen Gong Wu, the Monkey Staff.

Skills and abilities
A considerable genius in terms of robotic engineering and other fields of mechanical science, his armies of Jack-Bots are proof of this genius. (Granted, he lacks a certain degree of common sense, he has no humility, and his battle strategies are repetitive and seldom effective.) He occasionally modifies these models to have better defenses, more varied weaponry, or simply a new look to go with the episode's setting. Other valuable devices he has made have included a time machine (though he never had enough electricity to power it properly until the monks helped him in "Days Past") and a Shen-Gong-Wu-locating sensor, allowing him to rely less on Wuya.

While not a warrior, he has shown (although just slightly) above-average physical attributes in his numerous showdowns and Shen Gong Wu hunts. Still, without his robotic minions, he is largely defensless against the significantly stronger Xiaolin Warriors. Despite almost constant defeats at the hands of his enemies and rivals from both sides, he remains persistent.

Partnership Lists
Jack has had many, many allies. In chronological order, they are listed here:
 * Wuya
 * Katnappé
 * Xiaolin Monks (to stop Wuya)
 * Robo-Jack
 * PandaBubba
 * Vlad
 * Cyclops
 * Jack Spicer's Evil Dreamteam
 * Chase Young
 * Gigi
 * Tubbimura
 * Hannibal Roy Bean