5 years after fighting Goku at the World Martial Arts Tournament, Piccolo helped Goku fight Raditz. After his "Special Beam Cannon" attack kills Goku & Raditz, he trains Gohan to fight the Saiyans. He later dies protecting Gohan from Nappa. Later after being wished to Namek, he finds Nail & merges with him.
Piccolo is capable of regenerating