X, also known as SONIC.EXE, is the main antagonist of the official Sonic.exe game SONIC 2011, serving as the origin of Lord X, created by JoeDoughBoi.

An interdimensional entity who hails from the VOID, X is a being whose fascination with humanity and obsession with the Sonic the Hedgehog franchise created a destructive mix, forming a vessel for itself, with its goal being to spread and cause as much pain and suffering as it can go. It does this by playing various games, some subtle in its sadism, but always rigged to torture and manipulate the players that it forces into these games, using the souls of its new "friends" to fuel the vessels to play its games over and over again.