Antlers are unique to cervids and found mostly on males: only caribou and reindeer have antlers on the females, and these are normally smaller than
those of the males.

Each antler grows from an attachment point on the skull called a pedicle. While an antler is growing, it is covered with highly vascular skin called velvet, which supplies oxygen and nutrients to the growing bone.

In most arctic and temperate-zone species, antler growth and shedding is seasonal and controlled by the length of daylight. In tropical species, antlers may be shed at any time of year.

Antlers function as weapons in combats between males, which sometimes cause serious wounds, and as dominance and sexual displays.

In moose, antlers appear to act as large hearing aids. Moose with antlers have far more sensitive hearing than moose without, and a study of trophy antlers with an artificial ear confirmed that the antler behaves like a parabolic reflector.

Gathering shed antlers or "sheds" attracts dedicated practitioners who refer to it colloquially as shed hunting, bone picking or sometimes clinting. In Canada shed hunting usually occurs after the snow melts. Sheds often accumulate in one area, and these areas are often kept secret by those who hunt there.

Shed antlers have been used by craftspeople since ancient times to make tools, weapons, ornaments, and toys.

A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn (keratin and other proteins) surrounding a core of living bone.

Horns usually have a curved or spiral shape, often with ridges or fluting. In many species only males have horns. Horns start to grow soon after birth, and continue to grow throughout the life of the animal (except in pronghorns, which shed the outer layer annually, but retain the bony core).

Animals have a variety of uses for horns and antlers, including defending themselves from predators and fighting members of their own species for territory, dominance or mating priority.