1. Caine's homicidal, trigger happy friend in the 1993 movie Menace II Society.
2. To lose one's mind and become a fearless gangster. As heard in one of The Game's rap song... "it's the sequel to Menace and Oh Lord he done went O-Dog".
Now O-Dog was the craziest nigga alive. America's nightmare. Young, black, and didn't give a fuck.