Socks Monsters exist on Sock Planet. Sock planet is where all the socks go when the worm-hole in the dryer opens up due to build up of static electricity. Sock planet is the reason you only get 1 stocking at Christmas.
Sock Monster #2 was created by the Sock Witches, Sockmonster3 using dark magic. It is made out of socks and eats non-sock-based creatures. It store its food in a sack that was stitched out of socks.