KLINGON ANIMALS, #6, --- The Tribble...

This is not truly a Klingon animal in that it's not native to Qo 'nos, but tribbles are thought of when considering Klingon related animals because Klingons absolutely detest them, thinking them to be an extreme nuisance, to the point that they have hunted tribbles throughout the galaxy, intending to exterminate them as a species.  This is called "The Great Tribble Hunt", and Klingons are not ashamed to have participated in it.  

Tribbles were, in the beginning of their contact with humans, thought of as sweet and cuddly; they even purred aborably!  Then, they started to eat up all the food on the Enterprise, even the precious store of quadrotriticale.  This was the great problem with them...  They gobbled food, and "returned nothing".  Tribbles were first shown in an episode of the second season of the original series, "The Trouble With Tribbles" (1967). They have appeared in several subsequent series, as well as in a number of Star Trek feature films, and in video games such as Star Trek: Armada II.

A tribble

According to Star Trek canon, tribbles are native to the planet Iota Geminorum IV. They appear as small bundles of fur with no other visible features. Their coloring ranges from white and grey to black, as well as speckled brown, yellow and orange. According to Dr. Leonard McCoy's dialogue, their only two purposes in life appear to be to eat and to reproduce, and they perform both of these functions exceptionally well. McCoy concludes that tribbles use over 50% of their metabolism for reproduction and that they are born pregnant.

Due to their tendency to over-populate, Starfleet considers tribbles to be dangerous organisms and forbids their transportation. A creature genetically engineered to hunt tribbles was introduced in the animated episode "More Tribbles, More Troubles" (1973). The Klingons, in whose presence tribbles produce a convulsive, shrieking reaction, consider them "mortal enemies", as stated in the Star Trek: Deep Space Nine episode "Trials and Tribble-ations" (1996).

I just love the famous and hilarious line that Scotty utters at the end of the episode, "The Trouble With Tribbles" ---  "I beamed them over to the Klingons, Sir, where they'll be no tribble at all..."