According to Rob, the McPoyles are named after a family he knows from growing up in Philadelphia and, while they aren't as bizarre as seen in the show, they are extremely numerous.
When Charlie and the Mcpoyle brother's go to the police station at the end of the episode, the set for the police station is the same used in early Brooklyn Nine Nine episodes
Jimmi Simpson (Liam McPoyle) joined the series because he was friends with star Charlie Day.
This marks the first appearance of four recurring characters: the McPoyle brothers, as well as Charlie's Uncle Jack and his mom.
The set used for the McPoyle's apartment is used as Sweet Dee's apartment in later seasons.