WordNet (r) 3.0 (2006):

holy terror
    n 1: a very troublesome child [syn: terror, brat, little
         terror, holy terror]

Moby Thesaurus II by Grady Ward, 1.0:

105 Moby Thesaurus words for "holy terror":
   Dracula, Frankenstein, JD, Mafioso, Wolf-man, Young Turk, beast,
   beldam, berserk, berserker, bogey, bogeyman, bomber, brat, bruiser,
   brute, bugaboo, bugbear, demon, devil, dragon, elf,
   enfant terrible, fee-faw-fum, fiend, fire-eater, firebrand,
   frightener, fury, gamin, ghost, ghoul, goon, gorilla, gun, gunsel,
   hardnose, hatchet man, hell-raiser, hellcat, hellhound, hellion,
   hobgoblin, hood, hoodlum, hooligan, horror, hothead, hotspur, imp,
   incendiary, incubus, juvenile delinquent, killer, little monkey,
   mad dog, madcap, minx, monster, mug, mugger, muscle man, nightmare,
   ogre, ogress, phantom, plug-ugly, puck, punk, punk kid, rapist,
   revenant, revolutionary, rodman, roughneck, savage, scarebabe,
   scarecrow, scarer, she-wolf, specter, spitfire, spoiled brat,
   strong-arm man, succubus, termagant, terror, terrorist, tiger,
   tigress, torpedo, tough, tough guy, trigger man, ugly customer,
   urchin, vampire, violent, virago, vixen, werewolf, whippersnapper,
   wild beast, witch, wolf