Some dangerous echinoderms
Echinoderms are harmless animal. But in some situation, they are very dangerous. Usually, when they obtain food, there's toxin comes from their bodies. This toxin is poisonous. If echinoderms are being cooked, this poison in high temperature will be more dangerous. Example like sea cucumber, sea urchins, brittle stars, some of them are dangerous to touch. They will release the toxins to the prey. Those can cause very painful injuries.