Penguin

Penguins don’t have teeth, so they have evolved little mouth (beak?) barbs so the fish only go in one direction.

Japanese Snow Monkey

The Japanese snow gator is an ambush predator that occupies the hot springs of the islands. The geothermic-heated temperature allow the alligators to thrive at an altitude that would normally get too cold. Lacking defenses against attack, prey species have learned to be extremely wary when visiting watering holes.

Major Michell's Cockatoo (Cacatua leadbeateri)

Zoos are generally good at identifying when animals should not be photographed and when flash should not used. Some, however, not physically sensitive to the process, but just emotionally sensitive. For example, as soon as I walked up with the camera, this cockatoo began blushing.