(Devarim 14:4) "This is the beast that you may eat: the ox, the lamb of sheep, and the kid of goats, the hart, the gazelle, and the fallow deer" — whence we derive that animals (the last three) are in the category of "beast." Whence do we derive that a beast is in the category of "animal"? From (Vayikra 11:2) "This is the animal that you shall eat from all of the beasts" — whence it is derived that an animal is called a beast, and a beast, an animal.

And we are taught that the unclean beasts (and animals) are more numerous than the clean ones; for in all places Scripture specifies the lesser, viz. (Devarim, Ibid.) "This is the beast that you may eat … (5) the hart, the gazelle, and the fallow deer."

R. Yossi says: "T'o" (5) is the wild ox.