In "Bottom 10", The Cheat shivering and wet while standing next to a glass of water to dive into is a reference to exactly what Elmer Fudd does in the cartoon
In "Retirement", as Marshie says, "Just walk away, mother" (a reference to "Psycho"), the painting seen is drawn similarly to Hitchcock at the start of this show
In "High School", the "middle school" section spoofs the show, which features baby versions of some of the characters, plus Homestar as the nanny, whose legs are the only things of him one sees