long-spined sea urchin
... that spines of the long-spined sea urchin can break off in the skin and cause a painful sting?
... that spines of the <b id="mwCJ0"><a href="./Diadema_paucispinum" id="mwCJ4" rel="mw:WikiLink" title="Diadema paucispinum">long-spined sea urchin</a></b> can break off in the skin and cause a painful sting?