Frank Reynolds is the father of Dennis and Dee Reynolds, and potentially the biological father of Charlie. Frank also serves as a father figure of sorts for Mac, whose real father went to prison for dealing drugs. Despite his age and wisdom, Frank is not much of a better person than the rest of the gang and often serves as an indication of why the rest of the gang acts the way it does.Frank is as much of a schemer as the rest of them and quickly jumps at the chance to make money quickly. He is a fairly shrewd, if conniving, businessman and runs a series of business deals on the side while watching over his investment in Paddy's Pub. Frank claims to love his children and have their best interests at heart, but is all too willing to sell them out if necessary and often is particularly cruel to Dee.Frank is something of a kindred spirit to Charlie, who is his roommate. Frank and Charlie have been known to go on trash-collecting adventures together and don't often come across a piece of garbage they can't re-purpose.Frank has made an interesting group of associates around town, including an a capella singing group and a group of armed Asian gangsters who engage in some variety of illegal gambling and card games in the bar's basement. Frank also makes references to when he was in Vietnam, but it's soon revealed that he went there on a business trip in the early '90s.