Commander Kruge kept a ferocious monster dog as a pet aboard his Bird-of-Prey, to the left of his command chair. It died when two photon torpedoes from the USS Enterprise hit the ship. (Star Trek III: The Search for Spock)
Background information Edit
The term "monster dog" is not the "official name" of this animal; however, it is consistently used by Visual Effects Supervisor Ken Ralston during an interview in the Star Trek III: The Search for Spock (Special Edition) DVD, which discusses the creation of the puppet. According to magazine articles at the time of the release of the movie itself and, later, the DVD SE's text commentary by Denise and Mike Okuda, some of the members of the puppetry team dubbed it "Fifi Rebozo".
In the Universal Studios Hollywood theme park's Star Trek Adventure experience, a child participant would be selected to play a similar Klingon pet in each presentation. In the closing credits of the edited "episode," this juvenile creature was called a "puppy lizard."