TMDb/Regular Show: The Lost Ta Celebrity Regular Show: The Lost Tapes returns to Cartoon Network May 11th, reviving Mordecai and Rigby in untold park adventures from their past. May 4, 2026 AceShowbiz - Regular Show fans have a major reason to celebrate as Regular Show: The Lost Tapes is set to make its return to Cartoon Network this May. This long-anticipated spin-off series revives the beloved characters Mordecai and Rigby, bringing them back in fresh stories that explore unseen adventures from earlier in their lives working at the park.