Here's my list of cool animals that you will probably never see. They are mostly water type animals because those are the coolest.
The baiji is a type of dolphin that lives in a river in China. Maybe it's extinct, maybe not, but right now scientists can't find any.
from Alessio Marrucci on commons.wikimedia.org - CC BY-SA 3.0
Its skin is an inch thick, and instead of teeth, it has white bristles. Imagine eating with your mustache.
Emoke Denes on commons.wikimedia.org - CC BY-SA 2.5
A toad made of gold. Enough said.
Charles H. Smith on commons.wikimedia.org - Public Domain