Moose is the largest species of deer, but still a deer. Also, they're not horns, they're antlers. The difference between horns and antlers is that horns are made out of keratin (The same stuff as your hair and fingernails) with a bony core at the base of the horn, versus the antlers, which are made entirely of bone. Goats, rhinos, sheep, cows, and so on have horns. Only deer have antlers.
