Someone of suspicious character, questionable morals and low-no care for physical appearance and general personal hygiene accompanied by an inflated but unjustified sense of self worth. Possibly reproducing and in turn, discrediting Darwin's theory of evolution.
Hey - that kid with no front teeth over there looks like a bin rat.
Chicks who don't have their licences or minta cars so they just think they're the **** riding round with guys who have both of the aformentioned. Usually of the skank/chav variety, who think their binrats are great and buy them cigarettes and cheap alcohol, most likely in payment for sex.
"Dude look at that phat Rota!" "Yeah shame about the binrats in the back!"