The character is introduced in the second episode, but Hawley sought to cast Irwin, for his "playful approach to characters", during filming on the pilot, before the character's role had been written. Hawley "had to pitch him the weird, crazy character dynamic and that the show is about memory and identity", and Irwin agreed to join the project. His addition to the cast was revealed with the show's full series order in May 2016. Nicky Evans portrays Cary as an eight-year-old.
