He left the solitude of his cliff-side home to attend a family reunion against his better judgement. Unicorns are solitary by nature not just because they are introverts at heart, but because meeting in groups can be dangerous. Why, there were germs, viruses, poachers, and narwhals on the hunt for replacement horns to think about!
A week after the reunion his worst fears came true: an infestation of horn-eating beetles. They burrowed into his alicorn, carving out homes, laying eggs, and tickling him in places impossible to scratch! Legend has it the only way to cure such an infestation is to stab a virgin through the heart, but that just sounded rather medieval, foolish, and messy to him.
Still, he tried all the other silly-sounding remedies: ogre snot, troll spittle, and even dragon urine. Then he found a shaman and asked for help. The shaman smudged him with sage thrice a day for a week and soon the beetles moved on.
His alicorn still bore the signs of an abandoned beetle village and the caverns they left behind made an eerie, mournful hum as the wind blew through them. Soon rumors that his cliff was haunted spread throughout the land. The mailman grew too afraid to deliver the unicorn’s mail and he never had to worry about family reunions again.