Hermit crab
Alternative names: Paguroidae
The hermit crab is a small sized crustacean that can be found in all of the ocean waters. It has ten legs and 2 large claws with the left claw bigger than the right one as it serves as a weapon against predators.
The hermit crab is always in search for a new shell in order to accommodate its growing body so when the crab sees a shell that seems perfect it will grab it and quickly switch its abdomen from one shell to the other and if its shell is small and it can't find a larger one, the hermit crab has the unique ability to decrease in size.