Creator Justin Roiland recently gave a response on an attempted rape scene on Rick and Morty, "On the importance of Meseeks and Destroy’s darkest scene". That is nothing compared to the original concept of Rick and Morty which was attempt to get a cease and desist letter from Universal. You can see it here, NSFW. It extremely gross.
I'm somewhat amazed I didn't figure out that Rick and Morty are basically a version of Doc and Marty McFly from Back to the Future.