Warlock was a project for Wolfenstein 3D, made by MrWolf. It was made during 2002 or 2003, and was never fully finished. A 1-level version was released within closed circles.
The mod was based on the 1989 movie of the same name, featuring a magician who traveled through time. Many new graphics appear in the mod, including an impressive new status bar and numerous other graphics alluding to magic and the supernatural.
For most people the first notice of the mod came about when Atina uploaded a playthrough of the 1-level version on her YouTube channel.