Turdstein is a mod for registered Wolfenstein, made by Ryan Steinbruner. It was released on January 31, 2002.
The mod was never posted on the Wolfenstein 3D Dome news, but it was nevertheless hosted there. Furthermore, it was also available for a time at Ryan's own website.
As the title indicates, the mod features a bunch of juvenile graphics, mainly written messages and an edited enemy sprite. Two new levels are featured, on Episode 1, though the second level is based on Hans Grosse's original level.