I was wanting to make a horrorific comic-style bat, but instead of looking horrifying, he looks more like he's just been caught doing something he wasn't supposed to be doing. I liked that better anyway.
I made up a philosophy for pictures like this:
When in doubt
Black it out.
This method probably works best with "scary" pictures. I tried a few things on his fingers, like hair and tendons and veins, and nothing looked all that good. I colored it in black and then it worked better. This way the texture and dimension of his hand is created in the viewer's mind. That way it's as perfect as it can be. More black would have been even better, and I know this is a bad reason, but I didn't want to use up my ink pen on this practice doodle drawing.
There wasn't enough paper so his hand couldn't open up like it needed to (see below.)