Not sure about the poison, but it hurt like a .... Soaked my finger in vinegar and the sting went away after a while. We have since re-homed him. Beautiful, but dangerous. Looking to pick up a small purple pincushion now for my reef, but have a pencil, rock boring, and common urchin in my 180. The common urchin was smaller that a dime when he hitch hiked on a rock. Now the size of a baseball almost 2 years later. His name is spot...