Chameleon

The chameleon is a small lizard native to Earth.

While discussing the salt vampire's natural ability to take other forms, Robert Crater and Leonard McCoy discussed the similarity the creature bore to the chameleon, which possesses a natural ability to use protective coloring to survive in nature. 

Doctor Beverly Crusher would later compare the Tarchannen III species to a chameleon, as the skin of the lifeform has similar mimetic qualities. 

When Spock tried to match the sound of the Whale Probe to the sound of an Earth animal aboard the Klingon Bird-of-Prey HMS Bounty, a chameleon was one of the animals shown.