Quick facts about zoanthids! These anemone-like organisms can spread in large colonies and some are extremely poisonous! Zoanthids (Zoantharia, zoas, carpet coral, button polyps, colonial anemones). Zoanthid facts! Zoanthids are small, colorful anemone-like animals that are common in shallow tropical and subtropical waters. They are usually found on coral reefs, rocky reefs, rubble, sand, or mud. They can also live on animals like sea fans, sponges and black corals, often smothering their host a