Santa Claws 3D is a mod for registered Wolfenstein, made by LynxJSA. It was finished in December 1994 but did not see wide availability before it was uploaded on the Wolfenstein 3D Dome almost twenty years later, in February 2012.
The mod may be the earliest to alter the source code, as a new sign-on screen is present, in addition to changed episode names. Files are dated to November 29, 1994 and are thus more than three years older than those of Chokage and Assassinate Hitler.
The mod features 10 levels and many changed graphics and sports a Christmas theme. Some sprites from DOOM have been incorporated, including a shotgun guard now an elf with a large green hat.
New levels can be found on Episode 1.