Aristaeomorpha foliacea, commonly known as the green sea slug, is a species of marine gastropod mollusk found in tropical and subtropical waters. This sea slug is notable for its vibrant green coloration, which helps it blend into its algal habitat. It typically feeds on algae and is often seen on rocky substrates or coral reefs. The body of Aristaeomorpha foliacea is elongated and flattened, with a distinct head and a pair of tentacles. This species plays a role in the marine ecosystem by contributing to the grazing of algae, which helps maintain the balance of the underwater environment.