C'Thun is one of the Old Gods of the Warcraft universe, a vast and corrupting entity long feared in Azeroth, and Blade of C'Thun is a Hearthstone card tied to that dark power. The card appeared in the game's Whispers of the Old Gods expansion, when C'Thun-themed decks and corrupted minions became a major part of the meta. Players and editors later lifted its distinctive play sound for videos, streams and memes because it instantly signals an ancient, unstoppable threat. Its short length and ominous tone have kept it useful long after the expansion faded from competitive play.