As Dodge City's Deputy Marshal, Festus is the pride of the Haggen family, a clan of no-account hillbillies who may have less than 32 teeth among them. Although illiterate and often incoherent, the dog-eared Deputy has earned the respect of Dodge's townspeople as a capable lawman. And he is easily the most colorful resident of this frontier town. Festus is fiercely loyal to Matt Dillon and counts Matt as one of his two best friends—the other is his mule. His meager salary as a deputy forces him to do odd jobs to make ends meet, so when he's not covering Marshal Dillon's back, he's most likely painting a barn or digging a well to earn extra income.

Festus is a bachelor, which should come as no surprise given his educational background and lack of personal hygiene. In his spare time, he can be found at the Long Branch Saloon, waiting for someone to buy him a drink.