Three Wise Monkeys

The saying goes "see no evil, hear no evil, speak no evil."
Often depicted with monkeys, they are...

Mizaru, who covers it's eyes.
Kikazaru, who covers it's ears.
and Iwazaru, who covers it's mouth.

What's not commonly known is that there is sometimes a 4th monkey named Shizaru, embodying the saying "do no evil" and is shown crossing his arms, or... holding it's crotch, it looks like.