Crusty socks that became that way due to the wearer being a crazy hillbilly who never changes his or her socks. Considered quite the fashion (from North Carolina to Missouri) once they can "stand on their own two feet".
Kyle: uhh... dude... why are your socks standing up?
Leroy: I haven't washed them in a few years.
Jenny: ohhh Leroy... I just loooooooove a man who's not afraid to sport Hillbilly Crocks!