2011X is a fan-made reinterpretation of the entity at the centre of the Sonic.exe creepypasta, a horror story built around a haunted Sonic game that circulated online in 2011. The name combines X, the character's name, with the year tied to the original story. Clips of his distorted laugh spread through YouTube edits, horror game videos and meme compilations, where the sound became shorthand for a corrupted or evil Sonic. It remains popular because the laugh is instantly recognisable to fans of creepypasta horror and works without any explanation.