WordNet (r) 3.0 (2006):

evil spirit
    n 1: a spirit tending to cause harm

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "evil spirit":
   Baba Yaga, Lilith, afreet, atua, barghest, cacodemon, daemon,
   daeva, demon, devil, dybbuk, evil genius, evil spirits, fiend,
   fiend from hell, genie, genius, ghoul, gyre, hellion, incubus,
   intelligence, jinni, jinniyeh, lamia, rakshasa, satan, shedu,
   specter, spirit, succubus, supernatural being, the undead, vampire,
   yogini