6 Rick Potion #9

Morty is interested in going to the dance at his school with his classmate Jessica, so he asks Rick for a love potion. However, because Jessica has the flu, the potion becomes airborne and goes haywire, causing not only her but the whole population of Earth to fall for Morty save for blood relatives. Rick attempts to fix up an antidote, but he fails twice, ultimately causing all humans affected by the love potion to turn into mutated monsters called "Cronenbergs" (a reference to famous director of body horror films David Cronenberg). Meanwhile, Jerry visits Beth in her workplace because he is concerned about her fidelity, and they find Summer later. Rick and Morty then migrate to another dimension where their duplicates died soon after successfully curing all of Earth, thus allowing Rick and Morty to assume their roles. Post-credit scene: Jerry, Beth and Summer are happy to stay together as the only normal human family in their post-apocalyptic mutated world, glad that Rick and Morty are gone. Two Cronenberg versions of Rick and Morty come from the "Cronenberg world" to live there as well, because their home was inhabited by Cronenbergs all along, which were accidentally transformed into normal people.