Blue Velvet Sea Slug
Guardian: Barnaby Olson
These Sea Slugs eat small toxic flatworms, shooting out a short proboscis to suck them in. They tend to arrive at a place stay for a short period and then disappear. They probably follow the pattern of many species; arrive, consume almost everything, and then move on.
People buy these Slugs to remove flatworm infestations in their aquariums. Unfortunately, when they have eaten all the worms they can’t move on, so they starve to death.