Musician and movie star Asher Angel goes undercover as The Substitute. Asher is disguised as a snooty former child genius, an obnoxious world record holder, and an overeager competitive eater.

Superstar JoJo Siwa is transformed into The Substitute! Students on a space center field trip have a close encounter with Substitute staffer JoJo undercover as an unusual robot, a Pluto super fan, and a nerd who needs a major confidence boost.