Oimo is one of the two giants that guarded the front gate of Enies Lobby.
As a giant, Oimo is not only many times bigger then a normal human, but also equally many times stronger. As proven against the Kairiki Destroyers of the Franky Family, a mere human, no matter what the strength or size, will have no easy battle against them. Oimo and his partner Kaashii are natural born fighters. In the end it takes the efforts of the Galley-La's and Franky Family's best fighters, along with the help of Sodom and Gomorrah, to down both Oimo and his partner.
Source: