The McDonald’s dipping sauce made famous by Rick and Morty is Szechuan sauce.
McDonald’s originally created the sauce, also called Mulan Sauce, as a limited-time dipping sauce for Chicken McNuggets tied to Disney’s 1998 animated film Mulan. It was sold beginning in June 1998 and disappeared after the promotional campaign ended.
The sauce returned to public attention nearly two decades later when Rick Sanchez referred to it repeatedly in “The Rickshank Rickdemption,” the season-three premiere of Rick and Morty. In the episode, Rick describes finding the sauce again as a personal goal, turning a discontinued fast-food condiment into an internet sensation.
McDonald’s responded to the renewed demand with limited releases, including a highly publicized 2017 distribution and a broader return announced for 2018. Later releases have varied by country and date, so availability is not permanent. It is commonly confused with Sweet and Sour sauce because both are associated with McNuggets, but Szechuan sauce has its own Mulan-era origin and distinctive cultural history.