Those kids at your school that everyone hates because they're ridiculously
confident and cool. In fact, they're the only ones that don't realise that no-one likes them, they think everyone wants to be them (they're total dims). They wear the juicy sweaters and have the fake nails and are total {bitches}.
Originally, mip stood for Meanie In a Pot, from a stupid
inside joke the Mips had; complete with song that was enflicted on everyone.