I'm on an angry primate rampage

I recently read Our Inner Ape by Franz de Waal, and it was an amazing book that made me think I was an expert primatologist after having read it.
And now, as one of the world's leading self-proclaimed primatologists, I present you with some sketches of angry primates.
Also, remind me never to get a pet mandrill, no matter how colorful they might appear in the pet shop.

Sunday Painting: Viper

Snakes are rather interesting creatures. Their bodies have some special modifications on account of the fact they swallow their prey whole. They have double-hinged jaws, allowing them to swallow things bigger than their heads, and their skulls are divided into several plates, allowing it to be flattened and distorted and not block their airways during swallowing.
Basically, this means their skulls have lots of intricate hard-to-draw parts, and they look cool.
Also, this was the first time I've ever used a paint brush to apply ink. That was pretty fun.

Animal Skulls

As a celebration of my last day at work tomorrow, I thought I'd post some sketches I did from my image library at work.
I've drawn maybe 50 or so of these skulls, and after drawing 20 or so, I realized that I wasn't just drawing, I was learning design from the greatest designer of all. The lost and found lines, the way nature punches holes in things, the elegant sweeping forms the zygomatic arches.
Yeah, anatomy's pretty awesome.
Also, bonus points for anyone who can correctly identify the animals in the last picture.