Young Frankenstein Episode 83: Why does the crowd boo?

We continue with Dr. Frankenstein and his monster in lock-step of their tap dance routine. As Frederick pauses, it is time for the monster to get his solo and he begins to perform large pinwheels. The audience cheers with delight. Just as everything is going as planned, a light (or something) explodes, startling the creature. He stops and screams, backing away from the fire and the light. Dr. Frankenstein rushes forward and stamps out the bits of flame and demands they continue. He tries to restart his tap routine, but the music is silent. The crowd begins to boo and suddenly they throw heads of leaf lettuce at the two performers. Dr. Frankenstein begs them to not humiliate the monster. But, not heeding his own advice, when the monster begins to roar, Dr. Frankenstein demands obedience. His monster rebels, shoving the doctor backwards and knocking him out cold. Joining us again as our guest on the Wilder Ride is Matt Gray, former private detective and current land surveyor.