Gyakusatsu are a mottled blue in colour with slight tints of browns, greens and lighter blues. They are similar in look to the prehistoric animal, Onchiodon. Gyakusatsu has a large light blue and red spine decorating its head. Not much is known about this spine but the guild believes that they are used to create a large hole in the ground. This would explain the fact that gyakusatsu pray on frogs that live underground but primarily eat eels. When enraged gyakusatsu's gains large, blood red stripes on its underbelly and head.