Rick and Morty is a science fiction comedy on [adult swim] for teenagers and adults. It is about alcohol scientist Rick Sanchez and his grandson Morty Smith as they go through all kinds of weird interdimensional time travel adventures. They canonically appeared as themselves in a brief crossover appearance on The Simpsons, making an appearance in the couch gag for the episode Mathlete's Feat. It's also said that Rick knows who the Simpsons are and may be a TV show in the Rick and Morty universe.
Rick and Morty appearances in The Simpsons
Rick and Morty appeared in a couch gag in the episode Mathlete's Feat, where Rick and Morty crash through the wall in Rick's space cruiser and kill The Simpsons. Rick sent Morty into a portal to another dimension, where he had to get a serum to resurrect The Simpsons. When he returned, The Simpsons were brought back as weird, mutated versions of themselves that looked like Rick. They then took off, leaving them behind. Bart then commented, saying "No more guest animators, man!"
In "The Man Who Came to Be Dinner", Homer was sucked into an interdimensional portal, and as he left, he said , "And awaaaay, we go!", in reference to Rick's catchphrase, "And that's the waaaaay the news goes!"
In "Springfield Splendor", Dan Harmon was seen, teaching a college course on writing, giving a lecture about his "Story Circle".
The Simpsons appearances in Rick and Morty
A recurring background character in the show, has a T-shirt with a depiction of a blue colored head of Bart Simpson.
In the episode "Morty's Mind Blowers", Rick told Morty that he didn't label every one of Morty's erased memories, saying that "This isn't a Simpsons Halloween special". This was a reference to the Treehouse of Horror series and how every story in the episodes have some kind of title.