Fant is a warrior king from another dimension who first appeared as the main villain and final boss in Tanooki Hearts. He was summoned by Huff and an ancient tribe during the Ancient Times. He then created a plot and secretly teamed up with Xenahort to unlock Kingdom Hearts. However, YoshiEgg Nook, Rhode, and friends team up to stop Fant just before he can unlock Kingdom Hearts. At the end of the game, Fant's heart almost drains into YoshiEgg until YE finds the willpower to kill him.
Fant looks a lot like Zant from the GameCube/Wii game The Legend of Zelda: Twilight Princess, but there are some very distinct differences. For starters, Fant has metallic hands that look like armor, but are really prosthetics.