Leviathan is Squigly's parasite as well as being a fatherly figure towards her. He is a very loyal parasite to Squigly through and through as well as honorable. He has shown guilt whenever he felt like he put Squigly in a dangerous situation. He is said to be a gentleman, but sometimes, he has a dry wit when talking to his opponents. He also has a feral side since one of his attacks has him biting his opponents multlple times while dragging Squigly along. He is also shown to speak in an English accent.