Pinestar, former leader of ThunderClan, is Tigerstar's father and Leopardfoot is Tigerstar's mother. Pinestar ran away from ThunderClan to become a kittypet
Leapordfoot and Pinestar. He actually had two sisters, but they died when they were kits. The reason Tigerstar hates kittypets is because Pinestar became a kittypet on his last life.