I saw online: "Escargot Capri Pajamas"; whatever the hell those are.
Much like undergarments, slippers have the ability to protect the wearer while simultaneously and secretly building societies of bacteria and UFO bases (and subsequently, Bacteria In Black) for no purpose whatsoever (the slippers' purpose, that is). It's much like our own human existence, where we are so plentiful and seemingly far from exinction, but unlike dinosaurs and much like slipper bacteria, we are not badass with claws and feathers, etc., and all we can do is spread so people can write human/spreading-organism analogies about their own significance