Hydra

Hydra (scientific name: Hydra vulgaris) is a freshwater cnidarian of the family Hydridae. It is a small, predatory animal that inhabits ponds and slow-moving streams. Its body is up to 10 mm in length, and consists of a cylindrical trunk with a single, terminal mouth surrounded by tentacles. The tentacles are used to capture prey, which is then brought to the mouth for digestion. Hydra are found in temperate regions worldwide, and are common in Europe and North America.