A person that commits a lewd act in a public place. Panty-stealing, vampiric gothtards are the most widely recognized Public Perverts.
Girl 1: Wow, there's a creepy vampiric gothtard wanking off to a pair of panties in the library.
Girl 2: I know. That's Carlos D.
Girl 1: Wow, that Carlos D. is a Public Pervert.