Some of you may know this character, some may not. While others discuss whether he's an unique character or, due to R* laziness, random persons just share the same model, I decided to show my own theory about this mysterious character.
Watch from 1:45
Bogman asks the other Ballas' O.G. if he's sure that they can trust one of Grove Street Families' O.G.s (Big Smoke) or if it's just some kind of trap. Bogman gets told that he doesn't have to worry, because if it's trap, they'll kill them. He also gets told that GSF isn't a real gang anymore and crack changes everybody, even O.G.s want a slice of it.
Using CamHack, I've found out that Bogman appears even in the intro cutscene. After CJ comes back to Los Santos, he calls a taxi and Bogman comes to pick him up from Los Santos Intl. Airport (even though the scene was located in Francis Intl. Airport, Liberty City due to R* laziness). So, in order not to get the police suspicious about his involve in the huge drug operation started by Big Smoke, he decides to start working as a taxi driver. Also, have you noticed that Bogman, like all other main antagonists in 3D Universe (Miguel, Catalina, Sonny Forelli, Sonny's Right-Hand Man, Lance Vance, Frank Tenpenny, Eddie Pulaski, etc), also appears in the intro cutscene? It may suggest that he's actually one of the main antagonists in the game, but doesn't get killed just because CJ never finds out his activity.
Nothing special here, he just comes out of the toilet in Burger Shot and tells OG Loc that his "rapping" sucks.
Watch from 3:33
Bogman is seen snorting cocaine with Jizzy and his hoes and other associates. Since Big Smoke is buying drugs from the Loco Syndicate, it indicates that sometime between Madd Dogg's Rhymes and Ice Cold Killa missions he sends Bogman, just like Ryder, as his own represantive to the Loco Syndicate (or to Jizzy at least) to conduct the alliance.
So that's my theory.