Hydra

Freshwater lakes, rivers, and ponds, typically attached to underwater vegetation or rocks.

Carnivorous; feeds on small aquatic invertebrates such as Daphnia and Cyclops using stinging cells (nematocysts).

Mainly sedentary, but can move by "somersaulting" or gliding. Known for biological immortality as they do not appear to age and have extreme regenerative capabilities.

No risk to humans; benefits ecosystems by controlling small invertebrate populations and serving as a model organism in biological research due to its regenerative abilities.