Antler

Antlers are the large and complex horns of deer, consisting of bony outgrowths from the head with no covering of keratin as is found in other types of horn. While an antler is growing it is covered with highly vascular skin called "velvet," which supplies oxygen and nutrients to the growing bone; once the antler has achieved its proper size, the velvet is lost and the antler's bone dies. This dead bone structure is the mature antler. Antlers are shed after mating season and regrown each year.

The deer with the largest known antlers was the Irish Elk, now extinct. The currently extant species with the largest antlers is the moose.