WordNet (r) 3.0 (2006):

wild man
    n 1: a person who is not socialized [syn: wild man, feral
         man]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "wild man":
   adventurer, adventuress, animal, anthropophagite, barbarian, beast,
   brazenface, brute, cannibal, daredevil, destroyer, devil,
   fire-eater, harum-scarum, hellcat, hotspur, hyena, madbrain,
   madcap, man-eater, nihilist, rantipole, savage, shark, tiger,
   vandal, wrecker