OK, this is not a WTF, but I thought it was funny. If you have Ubuntu installed (or some other Linux that uses apt), try typing:
apt-get help
Notice that the last line says "This APT has Super Cow Powers.", then type
apt-get moo
And you get a nice ascii cow:
(__)(oo)
/------\/
/ | ||
* /\---/\
~~ ~~
...."Have you mooed today?"...