Yeah, Ptoing always makes faces like those. He can also lick his own nose and make funny noises!

Wacky looking fella. Maybe the inner mouth could be a little darker. I thik that would help boost the contrast.

Good style, personally reminded me more of ensellitis's work than ptoing's, but I do see the resemblance.  There really isn't a large enough jump between the colors used for shading to justify using so many, as Adam pointed out.  Same goes for eyes and teeth.  You could easily make this using no more than 8 colors and lose hardly any detail.

The red ghost is Blinky.  The others are Pinky, Inky, and Clyde.

You probably only needed to use one color for the shading, instead of 3.  I like the expression - it's very ptoing-esque.