Tardigrade. Also known as "moss piglet" and "water bear." They are practically indestructible. They can survive in more diverse environments than any animal on earth -- they can even survive in space!
The magnificent cat, of course!
I've just come back from the most fabulous birthday treat, a stay at the Big Cat Sanctuary in Kent. The organisation is involved in conservation globally, both through education and practical solutions to the problems caused by humans.
I hand-fed a tiger (the big boy that is my current avatar) and a black jaguar; and yet still have all my fingers intact.
I like them too -- my back yard's lousy with them at night. There's a cat purring in my lap as I type this.
I guess I'm pretty ecumenical in my choice of animals.