Top definition
When a Unicorn Stallion is defeated by dark magic, there is a slight, but noticeable chance of developing bump on one horn.

Noted Side-effects: Sudden urge to throw your wife at evil. Lack of relevancy to story arc.
Shinning Armor had a bad case of horn herpes...
by _Dr_Whooves_ November 11, 2012
Get the mug
Get a Horn Herpes mug for your cat Trump.