Zix, Travoltron, and Tee are space bandits that first appear in A Beautiful Mine. They attack Jimmy and his gang while they're collecting astrorubies and attempt to take the rubies for themselves. They later attack the gang while they are heading back to Earth. While Jimmy successfully gets away from the bandits, he has to sacrifice all the astrorubies to get out of Jupiter's orbit.
The trio are seen briefly near the end of Men at Work floating in space. The building of McSpankey’s flies by and they commandeer it as their new vessel, and make a cameo appearance in Win, Lose, and Kaboom.
They appear again in The Incredible Shrinking Town when everyone is tiny. Upon realizing everyone is much smaller, they plan to sell them to alien children as toys. Their plan is foiled when Jimmy and his friends, in their miniature state, pretend to be their conscience and turn them against each other, with Carl using ventriloquism to turn the three against each other.
The trio appears one final time in the League of Villains as part of the group the episode is named after, and is the episode in which they have their largest role. Their part of King Goobot's master plan involved sealing Jimmy's lab in green goo that will keep Jimmy from being able to get in. Tee is set to guard Jimmy and Sheen when the two are imprisoned aboard The Junkman's ship, and Sheen, whether accidentally or deliberately, forms a friendship with Tee, convincing Tee to leave with him and Jimmy when they escape. When they use their pod to reunite with Carl, Cindy, and Libby after crashing on a different planet, Tee initially frightens the three until Sheen convinces them that he is good now. When returning to Retroville while it's caught in a wormhole leading to prehistoric times, Tee is confronted by Zix and Travoltron about his decision to switch sides, but when they are cornered by a giant snake, Tee tries to convince Jimmy to help them, because even though they are still evil, they are still Tee's friends. Even after the N-Men rescue them, Zix and Travoltron refuse to be good until Tee convinces them that they have no reason to be evil. After saving Jimmy by telling the T-Rex to go eat Baby Eddie, they realize it feels good to be good, and abandon their positions in the League of Villains. After helping Jimmy and the others defeat the League of Villians and restore Retroville, Sam invites them into the Candy Bar and Zix promises to pay for the treats.
The space bandit trio may do bad things throughout the show, but they are definitely not the nastiest bad guys. Professor Calamitous, or King Goobot, or better yet, any of the other villains in The League of Villains, are the nastiest villain in the whole show. The space bandits are more anti-heroes than total monsters.
The bandits themselves are caricatures of Mr. T and John Travolta.