The Pastmaster was a villain that appeared in the cartoon series "SWAT Kats". He was an undead sorcerer from the Dark Ages who tried to conquer his home city, travelling through time using a mystic pocket-watch, and the Tome of Time, he was able to summon extinct or mythical creatures such as dinosaurs and dragons.

Although the tome was destroyed in his first appearance, he sought to transport Megakat City back to the Middle Ages where his towering castle used to be located outside the city, and he would become its ruler. But he would not rule it alone; every king needs a queen, and so he fell in love with Callista, Megalith City's ruler.