Any species of gastropod that glides along on a broad tapered foot and has no shell or one that is merely an internal plate or a series of granules.
Most slugs use the mantle cavity (see mollusk ) as a lung. Slugs have a soft, slimy body and live in moist habitats on land (except for one freshwater species). All are hermaphroditic. In temperate regions, the common slugs eat fungi and decaying leaves. Some tropical species eat plants, and some European species eat other snails and earthworms. See also nudibranch .