actually, you can also learn anatomy, by looking at a human, animal or whatever and quickly draw the shapes you see.. Don't think too much about it, just draw the head in proportion to the body, the feet and so on. The thing about anatomy is you wont ever get it right on the first try... I'm really trying to learn anatomy properly too, and what I do is look at magazines, try to draw the people(mostly fashion magazines because they often have very high quality pics). I also look at pics online... Also Try to find a good image of a skull, and draw it multiple time, or if you can, get hold of a science anatomy book and take it from there.
Of course... This is all serious stuff
May not be as fun as drawing random stuff, but I guarantee that once you got anatomy right, you'll be a much happier person, because your drawing will suddenly look so much more real and dynamic.
