The Hydra is a freshwater Cnidarian, related to jellyfish, sea anemones and coral polyps. Like their marine relatives, they have tentacles with small, harpoon-like stingers called nematocysts. The tentacles capture zooplankton prey and paralyze the tiny animals before putting them in the mouth at the base of the tentacles.
Hydras have 2 methods of reproduction, one way involving male and female cells (I have to be careful how I word things pertaining to this subject, the school filters will kick me off!). The other asexual method is by "budding", the hydra grows a new animal on its side. When the bud gets big enough it breaks off and becomes independent.