Penguin is an average-sized lean man with a black cap featuring a yellow brim and a red pompon (later replaced with a small emperor penguin decoration). He wears a beige overall with the Heart Pirates' Jolly Roger on the back and chest, along with brown boots. After the timeskip, he often dons a light blue yukata with the crew's emblem. He has a fun-loving personality, enjoys cracking jokes, and is fiercely loyal to his captain, Trafalgar Law. Though he gets along with most of the crew, he frequently bickers with Shachi. Despite his friendly demeanor now, as a teenager he was a bully who mocked others and started fights.