Gyuumaou

Gyuumaou is based on Nimwng OxDemonKing Ox Devil Lord or Ox Tyrant a character from the Chinese novel Journey to the West. Despite his threatening name he is really quite harmless and funloving given that Gyuu is the crest on his helmet it is incorrectly assumed by fans that Gyuu is his surname and Ma is his first. He was somewhat demonic and frightening when his castle became engulfed in flames on Frypan Mountain. He wreaked havoc through the village at the foot of the mountain threatening anyone he presumed would steal his treasure until Kamesennin showed him the error of his ways. He is Chichis father and thus Son Gokus fatherinlaw. Gyuumaouis very strong and trained alongside Grandpa Son Gohan under MutenRshis tutelage. As the series progresses Gyuumaous role lessens in the story and eventually fades into being a background character used only for slight comic relief. Gyuumaouis also the grandfather of Gohan and Goten. In anime filler he has a few large roles though from time to time mainly accompanying his family and the others. Source: Wikipedia