Kakisuke

Kakisuke is a talking monkey from Japanese folklore as well as a character in the series Hoozuki no Reitetsu. He became one of Momotaro's animal companions as penance for what he did to a crab. In the series he was sued by the crab's family on charges for "grievous bodily harm" after killing the crab by throwing unripe fruit at her. He regrets this to this day and mentioning the incident is enough to make him depressed. He is hired by Hoozuki after he is defeated together with Momotaro, and Kakisuke now works in Animal Hell together with Shiro and Rurio.

(Source: Hoozuki no Reitetsu Wikia)