Rabbit
Small herbiverous quadruped, generally living under ground in burrowed tunnel-systems. Traditionally supposed to have been itntroduced to England by the Romans, they were certainly t/here by the time of the Norman Conquest, as Domesday Book records established warrens of rabbits as a bankable resource of the king.
Commonly anthropomorphised, even in period, as cunning little blighters always after people's food, they also have a reputation for rapid multiplication [First rabbit: There are a pack of wolves coming. Second rabbit: Quick -- down this hole -- give it ten minutes and we can come out and surround them!].
Commonly alluded to as "bunnies" or "coneys" (but, apparently, not as "cunnies") they are also supposed to be part of the inspiration behind the hobbit of recent legendary.