Ptera-squirrel

Ptera-squirrels are a species of alien which appear in Games Workshop’s Warhammer 40,000 universe.

Description
Resembling common squirrels from Earth, Ptera-squirrels sport a coat of thick, soft fur and long, bushy tails. In addition, they possess a set of patagia: membranous flaps of skin which stretch between their forelimbs and hind legs. These patagia allow Ptera-squirrels to fly in the manner of terrestrial Flying Foxes or Sugar Gliders.

Biological Cycle
Whilst normally nothing more than cute furry scavengers, once in every few breeding seasons the Ptera-squirrels produce a generation of voracious, blood drinking carnivores. What causes this change in temperament is unknown to even the most learned of scholars, but the next generation of Ptera-squirrel will revert back to their peaceful selves and continue on until the next unexplained swing in demeanour. Unfortunately for the Ptera-squirrels, this has caused the Imperium of Man to designate them as pests to be exterminated whenever possible.