The most tragic character in the gang is Charlie, whose life was absolutely horrific from an early age and never really let up. His mother, Bonnie (Lynne Marie Stewart), has an obsessive disorder where she has to do things in threes (“Or Charlie will die,” she tells Mac) and germophobia, creating suits for she and Charlie to leave the house during a flu outbreak. She’s also a serious alcoholic, having rigged her suit with a beer straw so she didn’t ever have to go without. Bonnie loves Charlie, but left him to his own devices more often than not as a young child, which led to him huffing glue and likely causing brain damage. Said brain damage is also possibly why he started the series semi-literate and descended into writing in homemade hieroglyphics, as the huffing never stopped. He was also very likely molested by his uncle Jack (Andrew Friedman), writing a song and later a musical about the experiences.
In the bar where they all work, Paddy’s Pub, any work that’s deemed below the rest of the gang is “Charlie work.” He serves as janitor and exterminator, keeping the bar’s most basic needs met without ever getting thanked for it. He’s the glue that holds the bar, the gang, and the series together, giving it something resembling a beating human heart. He even gets his own moment of drama and catharsis a’la Mac’s dance in the season 15 episode “The Gang Carries a Corpse Up a Mountain,” crying out for his dead, absentee father. In the end he’s rescued from the situation by the gang in a somewhat heartwarming moment that reminds us that the gang are a (seriously messed-up) family.