Antlers are the branching bony structures that grow on the heads of male deer, moose, elk, and caribou. Antlers are shed and regrown every year, and they are used primarily for fighting and display during the mating season.

Antlers are composed of bone tissue, which is covered by a velvet-like layer of skin during their growth phase. This velvet layer is rich in blood vessels and nerves, which provide the antlers with the necessary nutrients and sensation to grow. Once the antlers reach their full size, the velvet layer dies and is rubbed off, leaving the bony antlers underneath.

Antlers can vary greatly in size and shape, depending on the species of deer or elk, and on the age and health of the individual animal. Antlers can also be used to determine the age and health of a male deer or elk, as older and healthier animals tend to have larger and more impressive antlers.

In addition to their role in mating, antlers can also be used for defense against predators or other males. Antlers are also sometimes used by humans for decorative purposes, as hunting trophies, or as a source of food or medicine in some traditional cultures.