Nappa is a saiyan who is a bodyguard of Vegeta. He came to Earth to destroy it's inhabitants use to sell it. Nappa faced the Z-Fighers. He killed Chiaozu and Tien. Next he fought Gohan, Piccolo and Krillin. He killed Piccolo and made Gohan mad. Gohan used the masko but failed. Goku join the fight and defeats Nappa easily. Nappa asked Vegeta for help but he got betrayed and blasted and killed by Vegeta. In GT, Nappa returns from Hell to look for Vegeta. But Vegeta confronts him and killed Nappa again easily.
Nappy in GT
Vegeta and Nappa on Planet Arlia