This sound comes from Metalocalypse, the animated television series centered on the fictional death metal band Dethklok. Instead of a plain censor beep, the show became known for using a brief guitar squeal to cover profanity, which matched its metal aesthetic. That choice made the censor itself memorable, and clips of it spread among fans making parody edits, adult cartoon memes, and bleeped reaction videos. It still gets reused because it delivers the joke faster and with more personality than a standard TV censor tone.