Philadelphia-born Rob McElhenney is known for his role in the FX sitcom It's Always Sunny in Philadelphia. Incidentally, he is also the program's creator, director and writer. His initial foray into acting was a struggle; he took on all kinds of acting jobs for several years in order to support himself. Now residing in Los Angeles, he is working in earnest with the show, which scored quite a coup when veteran actor Danny DeVito joined the cast for its second season. Mac is a co-owner of Paddy's Bar, Dennis' roommate and Charlie's childhood friend. He is also a bad-tempered brute, a man loaded with attitude problems. Back in high school, Mac served as the source of marijuana to the other kids. He is presently forced to engage in heroin trafficking through the influence of his father, who is doing time in prison because of drugs. Mac appears to be particular in capturing the attention of women, and constantly worries over how to get to them.