Mostel: If I appeared there, what if I did an imitation of a butterfly at rest? There is no crime in making anybody laugh. I don't care if you laugh at me.
Congressman Jackson: If your interpretation of a butterfly at rest brought any money into the coffers of the Communist Party, you contributed directly to the propaganda effort of the Communist Party.
Mostel: Suppose I had the urge to do the butterfly at rest somewhere?
Congressman Doyle: Yes, but please, when you have the urge, don't have such an urge to put the butterfly at rest by putting some money in the Communist Party coffers as a result of that urge to put a butterfly at rest.

Testimony before the House Un-American Activities Committee (HUAC), October 14, 1955, regarding Mostel's appearance at a Communist Party fundraiser.