Shawn introduces Gus as "Harry Monroe" to Polexia at Shangri-Lala. And he says he's trying to get an appointment with the doctor because Gus is "Stir Crazy." "Harry Monroe" is the name of Richard Pryor's character in Stir Crazy (1980)
At the psychiatrist's office, Shawn introduces himself and Gus as "Randle P. McMurphy" and "Cheswick." These are two mental patients' names in the novel and film "One Flew Over the Cuckoo's Nest (1975)."
David Naughton stars as the psychiatrist. This is a bit of an inside joke, as the plot involves a man claiming to be a werewolf, and Naughton starred as the title character in "An American Werewolf in London (1981)."
This is the second episode to have an on-screen title, particularly a movie-style episode title screen. The first was "Tuesday the 17th", and both episodes have a horror theme.
The scene in which Stuart wakes up naked with only balloons covering his privates is an homage to a scene in "An American Werewolf in London (1981)," in which the title character wakes up naked and steals a boy's balloons to cover himself.