A kangaroo
The kangaroo is a large marsupial mammal native to Australia on Earth.
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 kangaroo was one of the animals shown. (Star Trek IV: The Voyage Home)
- The scientific name for the kangaroo was shown as Martes pennanti, which is the scientific name of the Fisher (a weasel). We can assume that the computer on the HMS Bounty was incorrect.