Heehee, that's a good sketch, although I think you need to work on fabric folds. Most of it is fine, but the creases drawn on his stomach makes it look like his jumper is sagging off him when the outline makes him look tubby. (No offence!)
Erm, I've no idea what's going on with the ear 'cause there's no need for perspective unless the WHOLE BODY/object is at a certain angle. This one's just in a straight (eye-level) view so there's no need to change the angle of anything else for this particular pose.
Besides from that, the face is very well drawn, not to mention cartoony! ^_^ You don't get much of that in the MT forums as most of us specialize in Animé or realism. the only other crit I could give is that his arms seem a bit too big compared to his slim portrait (from head to shoulders, but this term can also mean a picture of a person's head that's been taken from the side), but that's nothing too important. Plus I have no idea who this character is or how his original body structure is like, lol, so please bare with me here.

Keep it up. =)