Fossa is the former 15th division commander of the Whitebeard Pirates.Fossa is a large and muscular older looking man, with a bald patch on the top of his head, a white mustache (black in the anime), a scar running diagonally across his face (on the head and forehead in the anime), and a chin that is split in two. He has Whitebeard's symbol tattooed in crimson on his right deltoid, along with three little circles, and he wears an open dark blue sleeveless jacket, with lighter edges, and loose light brown pants tucked inside his boots and are held up by a reddish-brown belt. He carries his weapon of choice; a katana with a square tsuba, on his left hip attached to his belt, but was also seen carrying it over his left shoulder with a long strap. He has been seen smoking a cigar in all of his appearances.

Thirty-years before the start of the series, Fossa had a fuller set of hair but without a mustache.