How to get your sister to say "Marx Brothers" while playing Pictionary:
First, draw the flag of the USSR.
Second, draw a statue of Lenin.
Once your sister starts staying things about communism, draw a book.
When your sister realizes this is the Communist Manifesto, draw a stick figure with a pencil, writing the book.
She will then, of course, say "Karl Marx."
Finally, draw three stick figures who look just like your stick-figure Karl Marx, and wait for your sister to guess, quite logically, "Marx brothers."
Do this in under one minute.
True story, as drawn by my brother and guessed by me, Thanksgiving Day 2012.