Fire Crabs are small turtle like creatures with six crab like legs and jewelled shells. They blast fire from their behinds when threatened. They are rated XXX by the ministry as very aggressive. Students learn how to clean up after a fire crab and restock its nest with straw without burning themselves as part of the care of magical creatures exam. Hagrid bred fire crabs with manticores to create blast ended skrewts. This is normally illegal under magical law of illegal breeding. Hagrid was sent to Azakaban as a result.