Jevil is the secret jester boss from Chapter 1 of Deltarune, released in 2018 by Toby Fox, and his laugh is one of his most recognisable traits. In the game he is a chaotic prisoner who delights in breaking rules and turning battles into unpredictable games. Clips of his giggle spread through Deltarune fan videos, edits and memes, where it became shorthand for madness, mischief and a character enjoying chaos. Because the sound is so short and distinctive, creators still use it to signal a twist or an unhinged moment.