In Wolf3D, there are 10 different map codes (0036 through 003F) that are listed as "Garbled image" walls. If used, they appear as walls with garbled textures. Here's a screenshot:
Pretty weird, don't you think? And to make it even weirder, while all garbled image walls of the same type (you know what I mean) appear as the same garbled texture and different types have different textures, the garbled textures that the 10 different types have often change as you do various things on a level (including pausing the game in any way.) In other words, if you enter an area with walls with a garbled door image and then leave it and do other things, when you return it could be a garbled column image. While the general thing to do with garbled image walls is to mix them randomly, you can also have a level where every section consists of a different garbled image wall type. Then, navigating the level could be tricky (and weird,) because sections of the level would change textures from time to time. Take note that like with all abnormal wall types, doors placed adjacent to garbled image wall types (including the sides of the door) will (usually) open and close without sound.