Eyesaur is a character from the One Night at Flumpty's horror game series, often shortened to ONAF, a fan-made take on the Five Nights at Freddy's formula where players survive a night against cartoonish monsters. The jumpscare sound attached to Eyesaur has circulated separately on soundboards and in fan edits, where it is used without needing the full game context. Because it is only a few seconds long and instantly reads as a horror-game scare, it has stayed popular for reaction videos, memes, and short-form edits that need a quick, startling payoff.