Those drawings are fine, although I would love to see one thats colored
Anyway my advice would be to try and draw other positions than the profile position(from the side).
Try some front-view or 1/3 view.
Although you drawing are nice, they can seem a bit too boring or static. So try and make it a bit more dynamic
Maybe draw two creature fighting, or one that's running.
This is all just suggestions though, so please don't take any offense