spooky

from WordNet (r) 3.0 (2006)

spooky
    adj 1: unpredictably excitable (especially of horses) [syn:
           {skittish}, {flighty}, {spooky}, {nervous}]

from Moby Thesaurus II by Grady Ward, 1.0

27 Moby Thesaurus words for "spooky":
      creepy, eerie, eldritch, fidgety, ghost-haunted, ghost-ridden,
      goosey, haunted, high-strung, jittery, jumpy, macabre, nervy,
      obsessed, ominous, possessed, specter-haunted, spirit-haunted,
      spooked, spookish, twittery, uncanny, unco, uncolike, unearthly,
      unrestful, weird