Selkies, also known as Water Wolves, live in any body of water. 

Their appearances change depending on the body of water. 

A Selkie's tounge always is sticking out, and mimics a fish tail in order to catch prey. 

Saltwater: 

Freshwater: 

A light blue color with a pale pink Mane and splotches. Their tongues are brown colored. 

Cave Selkies: 

These are very rare, and are dark colors with a bioluminescent tounge.