Anatomy Park

Anatomy Park is the first Christmas episode of .

Plot
It's Christmas, and Jerry tries to enforce the idea of a "human holiday" onto the rest of the family for his parents visiting, confiscating Morty, Beth and Summer's electronic gadgets. Rick then shows up with a homeless man in a Santa outfit he briefly introduces as Ruben before heading into the garage.

As the holiday progresses, Jerry realizes that his traditional idea of a family Christmas has been usurped by the introduction of Jacob, his mother's lover, who has entered a three-way relationship with his parents. While the rest of the family accepts and supports the relationship, Jerry becomes insecure and defensive, allowing his anxiety over his parents' relationship to negatively affect him throughout the episode.

Meanwhile, Morty finds out that Rick has created a Jurassic Park-style amusement park inside of Ruben named Anatomy Park. Rick shrinks him down to microscopic size and injects him into Ruben's chest cavity, allowing him to meet Dr. Xenon Bloom and the other residents of Anatomy Park. Ruben soon dies from a multitude of bacteria and viruses that have run rampant through his body, and the crew have to escape it to survive. As they make their way through Anatomy Park, Morty begins to fall for Annie, an employee of Anatomy Park, who begins the journey apathetic of his plight but who soon grows to fancy him. The crew discover that Poncho had planned to compromise the safety of Anatomy Park, to get back at Dr. Bloom, but he falls to his death trying to fight off the bubonic plague, with Roger drowning in feces soon after.

Meanwhile, Summer's boyfriend Ethan barges into the house asking why she has been ignoring all his texts, which leads to an argument. Jacob manages to bring Ethan to confess the source of his anger.

Back in the body, Dr. Bloom, Annie and Morty sit in a room watching an animatronic Ruben explain his history. The body soon begins to collapse and the crew have to try and ride a skeletal railway system (or, "The Bone Train") out to Ruben's nipple. Dr. Bloom is eaten alive by E. coli while trying to operate the bone train, whilst Morty and Annie are almost eaten by Hepatitis A, but Hepatitis C comes to their rescue.

Meanwhile, Rick puts Ruben's body into his ship and flies him, miniature Morty and crew out into space. He activates a growth ray on the corpse, leading to nationwide panic over the "naked sky Santa". The body soon explodes via dynamite Rick put in while picking up Morty and Annie, raining bloody chunks all over America and the Smith household.

Rick, Morty, and Annie arrive back at the house, where Annie reveals that she's been studying Dr. Bloom's work and has the knowledge capable to build a new one. Rick shrinks her back down, leaving Morty depressed (Rick waves this off by saying she has a "puffy vagina").

In the after-credits scene, Rick talks to Annie on speakerphone, where the new crew reveals plans to scrap Rick's special ride, "Pirates of the Pancreas". He hangs up on them and rants to Ethan, the site of the new Anatomy Park, about compromise. Ethan only responds "Cool...so when am I gonna get paid?".