Male elk and reindeer pack an impressive amount of weaponry on top of their heads, but it's an expensive arsenal. Every year the animals have to regrow their antlers, producing several feet of new bone as well as all the nerves, skin, and fur to support that growth. When the antlers are full grown, the blood flow stops and the velvet dries to be scraped off and expose the hard bone.

Since the growth happens so quickly-antlers go from nub to a full bone crown in just a few months- scientists are interested in this quick nerve regeneration. Some researchers believe if they could understand how the nerves in antlers regrow, they could help repair damaged nerves in humans.

To learn more about how Rudolph gets his antlers, check out this new Deep Look video.