Gat (also called Gato) is a character introduced in the "Even a Worm Arc" of Saiyuki Reload, though his full name—Gaty Nene Hawk—doesn't appear until volume 9. He's best known as Hazel's imposing bodyguard and constant companion, standing over two meters tall with the build to match.
Originally from a nature-worshipping tribe on the Eastern continent, Gat's backstory is tragic. When demons attacked despite a peace treaty, Hazel tried to intervene, but Gat opposed him—and became the first human Hazel ever accidentally killed. Hazel immediately brought him back through reanimation, but his own tribe rejected him as an abomination and cast him out. Gat sees his bond with Hazel as destiny, and it's shaped everything since.
He fights with a pair of highly accurate pistols, moving with surprising speed despite his size. What makes him truly dangerous isn't just his combat skills, though—it's that he can fight recklessly, even suicidally, because Hazel can resurrect him as long as there's a soul available (either stored in Hazel's pendant or taken from a nearby corpse). He doesn't eat, sleep, or need anything else to survive.
Reanimation left its marks. His eyes are yellow like all the resurrected, and he carries a permanent scar on his forehead from that first encounter with Hazel. He's almost eerily silent and emotionless in most situations, yet he's genuinely kind-hearted and pacifistic at his core. Goku apparently befriended him without much effort, and Gat seems to think of him as a friend—which says something about both of them. To Hazel, though, Gat is absolutely devoted, treating his commands as law.
Content compiled by AnimeList.moe from publicly available sources.