I had to agree with the guys down here. I really like the expression and the idea though. There's a lot of potential, i think.

 Do not use dithering, innovate in the shadows. And for that so much color around the corner? At first I thought I also saw how R1K. 

PS.: Sorry my english.

its not bad at all, but theres considerable amounts of banding on the eyes and the right side of the head by the highlight.  You can read about banding here: www.pixeljoint.com/forum/forum_posts.asp

also, I thought it looked more like a worm than a carrot ( like from this game: ps2media.ign.com/ps2/image/worms3d_art_100203_01_640w.jpg)

I think if you put some leaves on the carrot it would look more like a carrot.

Also the dithered shadow doesnt really work because you cant see it.  The shadow color and darkest purple in the carrot are too dark and cant be distinguished from the black at 1x.  I would replace those 2 colors with 1 color that serves both purposes, and make that color lighter so it can be seen against the black.

Good start. I'd say remove all dithering, then work as best you can on shading, volume and texturing. Dithering is 1- unnecessary; 2- advanced.

This piece would make a good candidate for the WIP forums, if you're willing to take it further =)