I'm curious about your decision to put human ears on him after all - what made you do it? And was it a conscious decision to give them the proportions that of a normal human being (top of ears pretty much aligned with the eye-level, and earlobe with nose)?

I can't see anything "wrong" with the model itself - I'm not so well-versed in Maya yet that I pick up on those few misaligned vertices

But from a design-standpoint I think you've got the look down well, making it look human, yet alien enough to catch that extra interest.

I do think that effect would be stronger without the horns, though. Had you gone for an emphasised cartoony style the horns might have been necessary to show the alienness, but since this has a realistic feel to it.. well, I think I would try without the horns at this stage of modelling