<Tr> <Th> Religion </Th> <Td> Roman Catholic </Td> </Tr> <P> Ronald "Mac" McDonald is a fictional character on the FX series It's Always Sunny in Philadelphia . Mac is Charlie Kelly's childhood friend and Dennis Reynolds's high school friend and later roommate . </P> <P> Mac is a co-owner of Paddy's, the self - proclaimed "Sheriff of Paddy's", and is generally the pub's most active manager . Mac is played by Rob McElhenney . </P> <P> Mac carols his signature line, "What's up, bitches?", throughout the series . In many episodes, Mac will enter the bar announcing "I've got news", or a variation on that basic idea, to set the episode's plot in motion . The others rarely share his enthusiasm, but he usually convinces one of them to follow him, though often reluctantly . Throughout the series, Mac flashes his signature "puppy - dog look" when he is ashamed or when he proposes something reprehensibly shameful . </P>

Mac from it's always sunny in philadelphia