Sonic.EXE is the central antagonist of his debuting creepypasta in 2011 along with a duology indie game created by MY5TCR1MS0N.
Sonic.EXE is extremely similar to Classic Sonic, but with notable differences. His fur is darker, and his arms seem to be "softer", and he smiles abnormally with his mouth being totally dark.
The main characteristic of .EXE is his black eyes with small reddish glowing pupils, and his eye sockets secrete slightly pink blood from his lower eyelids.