Hydra
(Hydra vulgaris)
Found all over the world in freshwater environments like ponds, lakes, and slow streams, except for Antarctica.
Ranges from 10 - 30mm (0.3 - 1.1in).
Feeds on tiny freshwater Invertebrates like Water Fleas, Copepods, Ostracods, Insect Larvae, and small Worms.
Disputed Biological Immortality.
The Hydra hunts by using its tentacles to paralyze prey and bring it to its mouth. Unlike regular creatures, the Hydra's mouth doesn't open or close normally. Instead it rips open on a cellular level before closing back up!
Besides regular reproduction, the Hydra can also reproduce by budding like a flower. Small Hydras grow and then split off. A more dangerous form of reproduction is also available... if it gets split into pieces those pieces can regenerate and grow into another Hydra.