I was doing some life drawing from 'The Drawing Script'. Great website by the way..Highly recommended for life drawing if you can't attend a live session and for motion poses that you can't get a live model to hold for you. Anyways, one of the poses was so action-packed and dynamic.. I had to convert it to batman!
The rest is just an idea that sprung from how some cats are always grumpy.. just like Mr. Batman.. so Bat-cat!
Hope you like it.