1. a stoner who tends to demand first hits on all bowls of weed and intercepts the joint/bong as it's being passed to steal an extra hit; pig-hitters also sneak hits in private before the official smoking begins to achieve a head-start on their high
2. used to describe an individual who converts an entire bowl of weed to ash before they pass the bong to the next person and take larger hits than their fellow stoners
3. one who abuses and beats pigs
Bob: *cough* Here, Gus, it's your turn.
John: Don't mind if I do!
Gus: Dude! You already went! It's my turn now!
Bob: Gosh, John, you're such a pig-hitter!
Dude1: What the...why is the bowl finished already?
Dude2: Aw sorry man, I can be such a pig-hitter sometimes.
Dude1: hey, why is my pig all bruised and shit?
Dude2: well, I got kinda bored and decided to beat it.
Dude1: what?! I never took you for a pig-hitter!