1.
the three wise monkeys (see-no-evil, hear-no-evil, speak-no-evil)
The famous trio of monkeys covering their eyes, ears, and mouth, representing the maxim 'see no evil, hear no evil, speak no evil'. Most strongly associated with the carving at Nikko's Tosho-gu shrine.
Also called 三匹の猿. The reading ざる is a play on words: it sounds both like 猿 (monkey, voiced as ざる in compounds) and like the archaic negative ending ~ざる ('not doing'), as in 見ざる ('not seeing').
The three principles
Cultural note
The most famous depiction is the 17th-century wood carving at 東照宮 in 日光. The motif has Buddhist origins and spread internationally, becoming a globally recognized symbol. Often used today to comment ironically on willful ignorance.