WordNet (r) 3.0 (2006):

enfant terrible
    n 1: a person whose unconventional behavior embarrasses others

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "enfant terrible":
   JD, bad boy, booger, brat, buffoon, bugger, cutup, devil, elf,
   funmaker, gamin, holy terror, hood, hoodlum, hooligan, imp, joker,
   jokester, juvenile delinquent, knave, little devil, little monkey,
   little rascal, minx, mischief, mischief-maker, mollycoddle,
   naughty child, pixie, practical joker, prankster, puck, punk,
   punk kid, rapscallion, rascal, rogue, rowdy, ruffian, scamp,
   scapegrace, spoiled brat, spoiled child, urchin, wag,
   whippersnapper