Generic Beasts have a tendency to turn up in Redwall fics. They occur because the fandom contains multiple sapient species, and sometimes the author forgets to specify which one a character is, which can be somewhat annoying. Generic Beasts resemble humanoids with fur and no snout, external ears, or tail which could possibly distinguish their species. Unless specified otherwise, their fur and eyes are dull grey.
A most egregious example was "zain" of "Blood omen," who was called a "half-breed," but the author never specified what either half was.