Titan is the largest of Saturns many moons. It appeared briefly in a memory in Morty's Mind Blowers.
An unnamed alien kidnapped Morty, Summer and Beth to this moon for an unknown reason. Upon a mountain, he made Beth choose which one of her children to survive the ordeal while they were imprisoned in spiky red spheres. She promptly chose Summer, much to Morty's disbelief, just before the arrival of Rick by portal. After shooting the alien, Rick explained that he confused Titan with Phoebe, another moon of Saturn.