Trivia: In "The Bob Next Door", Marge comments that a lot of people sound like Sideshow Bob, including Frasier from "Cheers" and "Frasier", and Lt. Cmdr. Tom Dodge in Down Periscope. Those are both characters played by Kelsey Grammer, who voices Bob.
The Simpsons (1989)
1 trivia entry for season 21
The Simpsons Christmas Special: Simpsons Roasting on an Open Fire - S1-E1
Continuity mistake: Lewis changes from black to yellow when Milhouse dares Bart to pull Santa's beard off. (00:14:10)
Skinner's Sense of Snow - S12-E8
Nelson: Hey, look how much Skinner makes: $25,000 a year.
Bart: Let's see, he's 40 years old times 25 grand. Whoa, he's a millionaire.
Skinner: I wasn't a principal when I was one.
Nelson: Plus, in the summer, he paints houses.
Milhouse: He's a billionaire.
Skinner: If I were a billionaire, why would I be living with my mother? [All the kids laugh at him.] They're just not responding to logic anymore.
Question: Which episodes feature the "Howling Dog" (usually used on outside shots of buildings)?