Mr. Sataan is introduced in the Cell saga of DBZ. He has the
title of 'Martial Arts Champion of the World' and the people on Earth think
he is a hero. They don't know that the Z warriors are way stronger than him.
The only people who know he is a phony are the King of the World who is a
dog, and the Tenkaichi Budokai announcer. They also know that the Z warriors
are the real heroes.
At first Sataan is very big headed and believes he can win any fight. When
Cell was killed by Gohan, Sataan made the world believe he was the champion
(the cameras stopped working near the end of the battle). In the Buu saga,
Sataan helped to save the world as he persuaded everyone on Earth to raise
their hands and contribute to the giant Genki Dama which killed Buu. He then
became friends with the Z warriors. In the final Budokai, they let Sataan
win all his battles to save his reputation, and he agreed to give them the
prize money if they needed it. His daughter is Videl. He is friends with Fat
Buu and they have a dog called Bee.