Ecology Of The Bloody Arduin's Kill Kitten For Your Old School Campaigns

 "Sire, Master Lane is here from the university's Monsters & Curiosities department again" 
" Your excellence we need to speak about the recent incursion of the invasive species known as the Kill Kittens" 
"Are you serious?!"
"These creatures are legend and myth!" 
"No sire the Kill Kittens are not a legend or a myth but a deadly reality" 

Portrait of a gang of kill kittens sizing up it's prey. 

Kill Kittens are some of the most dark & dangerous species of mimic animals that has made it's way from Arduin's dimensional shores. The kill kittens are an ancient form of biological weapons system that has reproduced thousands of times over. The originators of this species of vicious mimic animal are lost to history. 
The kill kitten has two very advanced tactics in it's arsenal of tricks & traps behaviors. The animal is a dedicated pack hunter who prays on human sized prey with advanced nerotoxin cocktails as a part of the glands that surround it's fangs & claws. Secondly, the 'kill kittens' are fantastic mimics who imitate normal cats and kittens hijinks and behaviors. 
These monsters are incredibly cunning and resourceful hunters with common packs of five to sixteen easily taking down a full grown human male in less then 2 minutes. The neurotoxin cocktail is designed to cause insanity and beserk rages as the prey experiences extreme pain as the poison ravages thier nervous system. The prey is driven into a beserk rage for 1d4 days making the prey vulnerable to further attack. 
 

("Kill Kittens" art by Greg Espinoza used without permission. 

The rumor is that kill kittens were designed by the Elves during the Human/Elven wars thousands of years ago. These creatures bare the hallmarks of occult and magical tampering on a biological level. The Elven nations  deny any such wrong doing but there are the hallmarks of Elven biological chimeral weaponization techiques. These characteristics include the incredibly cute mimic behavior that marks these incredibly dangerous pack hunters. 
Other hallmarks includes the line of sight teleportation that these monsters use to pounce on thier prey seemingly from nowhere. This magically fueled hunting trick is especially good for taking nice juicy hobbits a favorite of the little monsters. These monsters have been found as far away as Barsoom however. 

The nature of kill kittens is completely artificial with thier poison glands in thier mouth and claws able to pump neotoxins deeply into prey after taking it down. This ensures the death of the prey. The kill kittens also have a highly advanced cunning minds akin to lions or tigers. Packs of kill kittens use advanced scouts as decoys which often mimic acting hurt or injured behaviors to attract kind hearted fools who become prey for the entire pack. The kill can feed a pack for almost a month making thier murderous behavior hard to detect. 
The claws of a kill kitten are almost iron hard made of a hollow chiten that regrows over time with use as they shed the outer sheath. The muscle structure of a kill kitten is more akin to a lion or dire cat species. They have bite force ten times that of a lion relative to thier size. 

The kill kitten is sentient but not intelligent in the usual sense. Thier minds are cruel and centered on hunting, torture, reproduction, and expansion of the species. These creatures are unnatural hunters with minds twisted to evil and cruelty. Again there is the fact that many consider that these tendencies are because of an artificial biological weapon origin. 
The kill kitten has come to be regarded as a monster of legend but this has allowed the monsters to expand dimensional beyond the shores of Arduin. And over the last  two hundred years thier numbers have increased to become a menace of horror & violence.