Vampire bats adopt orphans, and are one of the few mammals known to risk their own lives to share food with less fortunate roost-mates.
402
Unsinkable Sam (nickname of a German ship's cat) who served on 3 warships, one German, two British, all sank in action. The cat survived each sinking, floating away on wooden planks to rescue.
19
There is a sea snail that wears a suit of iron plated armor. It is the only known animal to use iron sulphide as skeletal material.
9
Sergeant Stubby was the only war dog to be promoted to sergeant through combat in WWI. He saved his regiment from surprise mustard gas attacks, found and comforted the wounded, and even once caught a German spy by the seat of his pants, holding him there until American Soldiers found him.
16
Dolphins sometimes have fun by blowing bubbles and creating rings of air underwater, which they then swim through.
17