(Displays players and bots as skeletons. Robot skeletons can be enabled.
Note: I am aware of Angel_Mapper's Halloween Mask mutator and, as author of the original, I authorized the use of a version of the Skeletonizer within her mut. Since they are mutually exclusive options within her mutator anyway, I feel it's okay to release this as a separate mutator. This version includes team skins and more options.
A bright skin option makes skeletons white, or red and blue, if a team game.)
There's also a stripped down version with just the normal skeletons, they look like the third pic.
And now there's a version that supports four team colors for CTF4.