The Slug Monster resembles a giant green sea slug. She has a long, predominantly green, body that has three pairs of green legs. One pair of club-like antennae is seen on her head with two large eyes below them. Another pair of bent antennae is found near the end of her body. On her back is a long strip of purple where sacs that can hold smaller creatures are located.
Opisthobranchia Physiology: The Slug Monster has similar appearance and innate abilities akin to that of most opisthobranchs, specifically the sea slugs.
Sequestration: She has shown that she has the ability to capture smaller creatures and hold them in sacs located on her back.