Giatrus

Gon, The Stone-Age Boy or Giatrus (ギャートルズ, Gyātoruzu) is a Japanese manga written and illustrated by Shunji Sonoyama. It spawned two other manga, two anime television series, a television drama, and an anime film.

Plot
A comedy about the wacky prehistoric adventures of Giatrus and his tribe of the first human beings on the planet.