It is a saying and a concept as old as the hills. See no evil. Hear no evil. Speak no evil. Usually with monkeys doing it but frogs have been known to do it.
All of these pictures on this post were taken in the same store. Makes me wonder if they came from the same home.
Classic monkey form.
With the saying on it.
Then the Vegas version. Gotta wonder what the 4th guy represents.
Also note, none of the pictures have the monkeys in the same order.