Regular Show: Back to School

Regular Show: Back to School is an American animated miniseries developed by Sean Szeles, for Cartoon Network. The series serves as a prequel to the 2010–2017 series Regular Show. The series premiered on September 10, 2022; eight months after the series finale of the series revival. The series concluded on January 10, 2023.

Premise
The series takes during Mordecai and Rigby high school years and how their friendship was how it is today. In every opening and ending of each episode, either Rigby or Mordecai tells their past to their friends serving as a framing device.

Cast and characters

 * William Salyers as Rigby
 * Jon Heder as Mordecai
 * David Koechner as Principal Dean
 * Jason Mantzoukas as Mr. Ross
 * Roger Craig Smith as Francis Jablonski, Uncle Steve
 * Hayley Orrantia as Daphne Gonzales
 * Julian Dean as Don
 * Eddie Pepitone as Sherm
 * Courteney Taylor as Barbera
 * Ed Begley Jr. as William
 * Katey Sagal as Hillary

Development
During an interview behind Close Enough, J. G. Quintel had expressed interest in doing Regular Show again. A fan had pitched the idea of a prequel series to Quintel and his writing partner Sean Szeles with Szeles on board to develop and write, while Quintel serving as executive producer and creative consultant.

Casting
William Salyers was hired to reprise his role as Rigby for the series, while Jon Heder was cast as Mordecai for the sake of Quintel to resume his work on Close Enough. Roger Craig Smith, Julian Dean, Eddie Pepitone, Courteney Taylor, Ed Begley Jr., Katey Sagal, Jason Mantzoukas, and David Koechner reprise their roles for the supporting characters. Hayley Orrantia was cast as Mordecai's ex-girlfriend Daphne Gonzales, replacing Linda Cardellini.