Coral

     If you don't know what coral is, I get you. I have spent years hearing about coral reefs without knowing what coral is. They may seem like one big rock or shell, but that is true only if you look from a distance.

    A coral colony contains many polyps. Polyps are technically animals. They have tentacles that search the water for plankton to kill and hunt and a gut to digest the food. Although they hunt, most of their sugars come from algae living in their cells. These algae can photosynthesize enough for themselves, so they pay some rent and give the polyp some sugar. If the polyps survive and don't get put into somebody's living room collection (I can't be talking), they make identical clones. The result is a system of polyps.