An end-o is a stoppy that went to far and you go end-o[ver] end. Front wheel stand is the only other name I can think of. I've done both stoppies and end-o's. endos are no big deal at low speed just tuck into a summersault (chin to chest don't look up) and don't try to save the bike, its tough it can take it, save your self. I've had no injuries using that method on smooth ground (as opposed to roots and rocks).