The Collaborative International Dictionary of English v.0.48:
Creepiness \Creep"i*ness\ (-[i^]-n[e^]s), n. An uneasy sensation as of insects creeping on the skin. [1913 Webster] She felt a curious, uneasy creepiness. --Mrs. Alexander. [1913 Webster]WordNet (r) 3.0 (2006):
creepiness n 1: an uneasy sensation as of insects creeping on your skin