The three monks are animated versions of three Teen Titans comic book creators: The man with the glasses and white hair is classic Teen Titans artist Nick Cardy; The man with the gray goatee is New Teen Titans artist and co-creator George Pérez; And the thin man with glasses in New Teen Titans writer and co-creator, Marv Wolfman.
Raven's bedtime story is a quick and amusing recap of the events from season four.
Timmy Tantrum, Teether and Melvin are characters created specifically for the animated series.
Spotted on the train are animated versions of character designer Derrick Wyatt and storyboard artist Irineo Maramba.
After being raised to suppress her emotions on Azarath, Raven often felt out of her element on Earth. She often had problems relating to other people, and would withdraw from such situations.