Horn
From Tardis Wiki, the free Doctor Who reference
On Earth in the distant past, Ian Chesterton found an animal skull with no horns or antlers, suggesting that it came from a horse (TV: An Unearthly Child) or deer. (PROSE: Doctor Who and an Unearthly Child)
The Judoon had horns. Removing the horn of a Judoon captain was considered a dishonour and therefore the worst of insults. (TV: Fugitive of the Judoon)