These creatures are foul things that prey on the weakness of loss. Their home society, and indeed, their home, in completely unknown, as all that have been found have been killed to out standards.
Woodrats - In a fantasy realm of cooshee (elven dogs/cats) it is to be expected that there is some sort of elven vermin. These mercurial rats are lightning quick, and are capable of hiding in plain sight. Other than this, they have no special ability.