Bluebeard(n.) The hero of a mediaeval French nursery legend, who, leaving home, enjoined his young wife not to open a certain room in his castle. She entered it, and found the murdered bodies of his former wives. -- Also used adjectively of a subject which it is forbidden to investigate.
Thesaurus Entries
Bluebeard, Cain, Mafioso, Young Turk, apache, assassin, assassinator, beast, beldam, berserk, berserker, bloodletter, bloodshedder, bomber, bravo, brute, bucko, bully, bullyboy, burker, butcher, button man, cannibal, cutthroat, daisy, demon, desperado, devil, dilly, dragon, eradicator, executioner, exterminator, fiend, fire-eater, firebrand, fury, garroter, goon, gorilla, gun, gunman, gunsel, hardnose, hatchet man, head-hunter, hell-raiser, hellcat, hellhound, hellion, hit man, holy terror, homicidal maniac, homicide, hood, hoodlum, hooligan, hothead, hotspur, humdinger, incendiary, lulu, mad dog, madcap, man-eater, man-killer, manslayer, massacrer, matador, monster, mugger, murderer, pesticide, poison, poisoner, rapist, revolutionary, rough, rowdy, ruffian, savage, she-wolf, slaughterer, slayer, spitfire, strangler, termagant, terror, terrorist, thug, tiger, tigress, torpedo, tough, tough guy, trigger man, ugly customer, violent, virago, vixen, wild beast, witch, wolf