Sonic.exe began as an internet creepypasta character, a corrupted, demonic version of Sonic the Hedgehog, and later appeared in fan-made horror games and animations that spread through YouTube and gaming communities. The character's distorted voice and sudden screams became shorthand for creepy Sonic content, shared in horror compilations, reaction videos and memes. It remains popular because it instantly signals danger and parody at once, letting creators reference a well-known internet horror figure without needing any setup or explanation.