Mountains, yaks and a pen

I've been tripping out drawing microcosms on the backs of animals. Here's one I recently finished. I was originally going to do it for @sirsensei's drawitbetter contest but didn't start drawing in time... After a load of procrastination, I have finally managed to finish a yak with some mountains on its back. The drawing is approx 12x8cm.

Here are a few pictures showing the process

Happy Steeming!