Underwater Snakes are minor characters in 12 Oz. Mouse.
These snakes are see-through snakes with blonde hair, a small dotted eye and a skeleton in their serpent bodies that swim and travel in the waters of The World of Muck, as the one of the few fauna that is inhabiting the underground mucky world, with the only other creature being Spider. They have only appeared in the episode "Because They Could". These snakes are also heard hissing at Roostre.
- These are one of the few snakes in the series with others being; Black Beast, the Fire Breathing Snake and the bloody snakes we saw come out of Mouse Fitzgerald's body in "Auraphull".