Dolphins sometimes have fun by blowing bubbles and creating rings of air underwater, which they then swim through.
17
The colossal squid has the largest eyes in the world.
4
The Pistol Shrimp can snap its claws together to create a sound of 218 decibels, louder than as supersonic jet at full speed. It only lasts for 1 millisecond. The snapping action also creates a bubble that is greater than 5000 Kelvin, close to the surface temperature of the sun.
21
Some lizards, in which the tail is a major storage organ for accumulating reserves, will return to a dropped tail after the threat has passed, and will eat it to recover part of the sacrificed supplies.
13