Not bad. better than my drawings so far Though I'll have to say the neck looks kinda like it's getting vacuumed up into his head.
Maybe just widen the top of the neck a bit.
And his hands look slightly missproportioned. (i.e. they're too small)
Remember that hands are nearly as big as their host's face. This can vary just like any other part of the body (people aren't perfect after all) but that's a general rule I go by.
So, I think if you were to make the hands slightly larger and widen the neck at the top a bit more it would be one kick ass picture. ;)
Hope I helped :D (and if you think this is a harsh review you haven't seen me pick apart my own work, LOL, it's worse than Ebert and Roper reviewing a movie ;) :D )