Melissa Rauch made a surprise guest appearance in the third episode of HBO Max's "Stuart Fails to Save the Universe," playing a monstrous, 60-foot version of her "Big Bang Theory" character Bernadette Rostenkowski. Speaking to Variety, Rauch revealed that series creator Chuck Lorre approached her with the idea, promising a version of Bernadette unlike anything she had played before, giving longtime fans of the sitcom an unexpected and wildly different reunion with a familiar character.

In the episode, titled "Spoiler: Bert Is Magic," the show's characters travel to a universe governed by magic rather than science, where Bernadette is revealed to be a demon posing as a "master sorceress." After tricking Stuart into providing the "blood of an innocent" for a spell, she transforms into a giant monster and destroys Pasadena before being thwarted, with the help of wizard characters played by Brian Posehn and Wil Wheaton, who also reprises his "Big Bang Theory" role.