Hatena

Hatena (Hatena arenicola) is a one celled organism recently discovered in Japan. It is a flagellate and can resemble a plant or animal, acting as predator in one stage of its life, then carrying a photosynthesizing alga inside itself in another, appearing much more like a plant. Researchers believe that this organism is in the process of endosymbiosis where one lifeform incorporates itself into another, resulting in a completely new lifeform, in the same way that plants and animals diverged.

The name is from a Japanese interjection meaning roughly "how odd".