Medusa

The Gorgon; or one of the Gorgons whose hair was changed into serpents, after which all who looked upon her were turned into stone.

Any free swimming acaleph; a jellyfish.

one of two forms that coelenterates take: it is the free-swimming sexual phase in the life cycle of a coelenterate; in this phase it has a gelatinous umbrella-shaped body and tentacles