He is Chichi's father and thus Son Goku's father-in-law. Gyumao is very strong and trained alongside Grandpa Son Gohan under Muten-Rôshi's tutelage. As the series progresses, Gyūmaō's role lessens in the story and eventually fades into being a background character, used only for slight comic relief. Gyumao is 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.
Voiced by: Gouri Daisuke