I really like the expression, but there are some anatomy mistakes. The waist is a bit too skinny and the arms kind of stick-like. Also, try not to draw using too many lines because although it gives that "sketchy" look, it can also make it look hairy/furry. Try to use a reference picture with a similar pose to compare to look for any mistakes you might have made. Or just look in the mirror.
And you might want to add some clothing folds.
But seriously, other than that, its pretty good!