This sound comes from Death Note and is associated with Light Yagami in his Kira persona. The anime adaptation aired in 2006, and Kira's laughter became one of the series' most recognizable vocal moments. Online, the clip spread through anime compilations, villain edits and reaction memes because it instantly signals superiority, madness and a dramatic plot twist. It is still widely used when creators want a recognizable anime laugh that feels both iconic and unsettling.