The drawing style is pretty good and Golbat almost looks perfect. However, I'm not sure if the spots on its body and the white on its legs are supposed to be shading or what, but it doesn't look right. If that's what that stuff is supposed to be, then you did a poor job of shading. The shading on the wings look great, though.
Also, as critique and from being a Pokemon fan for a long time (haha) I know that Golbat's body is more long than round.
This is definitely a cute little drawing, but it has it's issues.