Here's a few more.
The Know-It-All
Yeah, the title is self-explanatory, but this guy usually knows everything about everything related to pool. He can remember where balls were during a match played 20 years ago. He knows who should play whom, and for how much, and what the line should be. He knows how much gas it takes to get from poolroom to poolroom, and when the traffic lights will work in your favor...well, you get the picture! Meanwhile, he has not bet a nickel in decades!
The Professional Railbird
This guy sweats every tournament, regardless of payouts and caliber of player. He will also sweat every match if something...anything is being wagered. He does not play...ever.
The "I wanna be here but like to act like I don't" Guy
He can't imagine spending his time anywhere else but the poolroom, but when he is there he barely sweats any match, does not bet anymore, and does not play. Even at the U.S. Open arena he'll pay admission to be IN the arena, but won't actually watch any match in its entirety...he just wants to be there.
The "I'm too cool to clap" Guy
Loves pool, loves great competition...but would rather die than applaud for anything...no matter what the occasion!
The Slut
We all know her. She has a rep for sleeping with everybody within the tri-state area that can make three balls in a row. Her own pool-playing ability is sorely lacking.
The Man-Whore
Has to sleep with or pursue any attractive or semi-attractive woman that holds a pool cue. His pool-playing ability is usually lacking as well.
The Cheapskate
Name is also self-explanatory, but you know him well. Every room has one...or three.
The Pointless-Practice Man
This guy will practice a highly improbable 4-rail kick shot for three hours. Won't practice any fundamentals, no basic drills and won't play anyone else...but for some reason he gets mad when he doesn't have success in tournaments.
The APA "Qualifier"
This person just started in the APA, and insists on telling anyone how they beat a higher-ranked player recently. Even worse, they choose to measure their progress by their APA ratings. They are immensely proud because they went from a 3 to a 4, but then they play someone who can actually shoot and they get crushed emotionally.
The Temper-Tantrum
Will destroy anything (stick, case, table) because they are furious about missing a shot. These are usually the easiest people to beat. Just play them safe when you have a clear out and you can see the steam coming out of their ears...