Not a big Night at the Opera fan except for the stateroom scene on the ocean liner.
Scene: A overcrowded stateroom with people all over each other including Harpo fondling a pretty girl. Knock at the door. A mechanic is there. Groucho opens the door.
Groucho: What do you want?
Mecahnic: I'm here to turn off the heat.
Groucho (pointing at Harpo): Good! You can start with him!
Great scene in that movie. One of my favorite in Duck Soup was .........."So you refuse to shake my hand!!!" (Groucho).