Bill Cipher is the triangular dream demon and main antagonist of Gravity Falls, the animated mystery series that aired from 2012 to 2016. The character became a lasting fan favourite because of his chaotic humour, cryptic deals, and unsettling charm, and short clips of him continue to circulate in fan edits, reaction videos, and meme compilations long after the show ended. This particular sound is used online as a quick shorthand for villainous control or a mischievous takeover, which keeps it useful for creators who want an instantly recognisable Gravity Falls reference without a long scene.