Sonic.EXE comes from a well-known Sonic horror creepypasta that spread widely online in the early 2010s, later inspiring fan games, animations and meme edits. The character’s laugh became a recognizable audio cue in that wider Sonic.EXE fandom, especially in scary compilations and jumpscare videos. It still shows up because people instantly connect the sound with corrupted Sonic imagery, red-eyed reveals and retro horror parody. Even outside fan projects, creators use it as shorthand for a familiar game character becoming creepy.