What Sea creature is coral related to?

Coral is related to jellyfish and anemones. They are all part of the phylum Cnidaria, which includes animals with radial symmetry, stinging cells, and a gastrovascular cavity. Coral polyps are small, colonial animals that secrete a hard exoskeleton made of calcium carbonate. They live in colonies that can form large structures, such as coral reefs. Jellyfish and anemones are solitary animals that do not build exoskeletons.