'Shame'
After two full seasons of Ryan living alone, Ryan decides to get a roommate after Jenna receives his final mortgage payment warning and offers to give him $1000 for 'dog-sitting' Wilfred. Ryan refuses, feeling embarrassed, and tries to clear the upstairs for a new roommate. Wilfred has decided to make the upstairs a bachelor pad of all things filth, since he thinks Jenna's house is too clean.
Ryan makes the upstairs liveable and finds a clean, normal male roommate, but Wilfred finds a way out of living in a too-clean house. Anne, a down-on-her-luck, walking-dumpster, played by Kristen Schaal from 30 Rock tries to move-in, but Ryan tells her he's already filled the vacancy.
While Ryan's out, Wilfred emails her and tells her to move in right away, making her pay three-months rent upfront, so it's impossible for Ryan to kick her out when he finds her on his couch.
Despite her filth, Wilfred convinces Ryan to get to know her. Ryan makes a solid effort, but after Anne reveals her "small internet business" is having creepy men pay to watch her eat, Ryan's tolerance dwindles. Wilfred also ruins Ryan's interview at a law firm by putting garbage in his briefcase.
Wilfred on the other hand, is in heaven, he follows Anne around eating the food that she drops or leaves in her sheets. He becomes so fat that he has to wet a fake tongue on a stick in order to lick the places he can't reach.
Ryan finally loses his patience with Anne and yells at her to move out. However, Ryan then feels bad seeing that Anne needs some help getting back on her feet. He helps her get a job as a temp in an office and cleans up her act, but realizes that her being "normal" doesn't make her happy. So Anne stays as his roommate.
Image credit: Fox/FX