Fixed up your laugh a little bit. He looked like he was playing with his jaw or yodeling or something. The biggest problem here was the face distending on the bottom jawline and not the overall head/face. You laugh with your whole face, not just your mouth, which means your whole head gets involved, scalp, jaw, and all -- I probably even should have put some movement in his shoulders too, but you get the point. Laughter is a pretty intense emotional expression, so your body gets into it a whole lot more than simply a smile and an open mouth.
The hair 'animation' was added in, particularly where the face stretches far outward (i.e. during the laugh), on both the scalp and chin-fuzz, which is just some slight movement in the pixels in the hair/chin in order to keep the head/face/skin from seeming so stiff (because that stiffness really adds to the 'creepy' factor unfortunately -- and, if you're going to keep the eyes, you might really consider fixing as much of that 'stiffness' as you can.)
Speaking of the eyes, if you don't mind compromising a bit with people who think the eyes are too creepy, I would suggest perhaps using a dark grey like in the shadows of the teeth to represent the whites of the eyes if you like the dark color on the eyes -- unless you just really really don't want pupils for some reason. If that's the case, I managed to modify the eye & eyebrow shape in the laugh so that it at least works a little better with these dark eyes to convey genuine laughter of some sort.
And as for your "tourette" animation, I was giving you a complement -- my computer just can't seem to display the frame changes that quick, so I made mention of the timing being just a tad too fast. Didn't intend to sound like I was criticizing you.