Baby is a fictional parasitic extraterrestrial supervillain in Dragon Ball GT, based on the Dragon Ball manga created by Akira Toriyama. He is the series' first main antagonist, as well as the longest running villain in the show's run.

Initially, Baby is single-minded in reviving the Tuffle race and exterminating the Saiyans. Over time, it is shown that he is cunning enough to dominate the Z Fighters, possessing Vegeta and successfully restoring the Tuffles' home planet. However, Baby is also incredibly childish and immature; he is very prone to taunting, and flies into a rage if he is teased enough. Ironically, despite seeing the Saiyans as a barbaric race, he displays enjoyment in battle as well

(Source: Wikipedia)