Zack's signature appearance is a tall, well-built man with spiky black hair, and the iconic sky-blue "mako eyes" common to SOLDIER members. He dresses in black uniform, wearing gloves and boots, and wields the Buster Sword. He also has an X-shaped scar on his cheek, a silver stud earring in his left ear, and a single lock of hair hanging down in front of his face. Zack is upbeat, optimistic, kind, and driven, beaming with enthusiasm and energy. He's referred to as "Zack, the puppy." by peers.