This is the pupae stage of the Dynastor darius butterfly. It looks uncannily like a viper's head, and even moves to appear its going to strike when potential predators are around. Me? I have no natural defenses and get picked on all the time. If I were a butterfly my parents would have been eaten before I was even born.
Apart from its realistic impression of an alert viper, this creature has another trick up its sleeve - it is able to sense the world outside and react appropriately from inside its cover. So when a predator approaches, the pupa can sense movement and swing its shell back and forth, creating the illusion of a moving snake that's ready to attack.
Mother Nature: she never ceases to shock and amaze. Or get wasted and drunk dial me asking to come rub her branches. I don't even know what that means, but I did hang a tire swing from her once. I asked her if I could carve my initials into her trunk but she said she wasn't ready for that commitment. That's when I told her I didn't care and I was really in love with the Giving Tree anyways.
Keep going for a bunch more shots.
Thanks to Lucas, who has a bear shaped sleeping bag for the exact same reasons.