I love this drawing. You've got so much character in there. It makes me smile
It's curious you say it was done in pencil because it very much looks like charcoal (a wonderful medium). In terms of correctness of features, there just seems to be a slight distortion: his eyes and nostrils are on a diagonal (going downhill from left to right) but his nose and forehead are straight up and down. However, there's not very much in it and it doesn't spoil the drawing for me.