Appearances in Canon Games
In Fan Club, there are three monkeys, where one in which is the player. Per the actions you are supposed to follow in this game, the monkeys do the clapping, or otherwise "cheering."
Rhythm Heaven Fever
In Hole in One, the Monkey is seen as one of the two main characters. It is the one on the right side of the screen tossing the golf balls at you to shoot. In Hole in One 2, the Monkey is instead female.
The Monkey is the leader in Tambourine. It plays the tambourine as the player must repeat them.
In Monkey Watch, there are dozens of monkeys. The player, a monkey as well, rides the watch's clock hand and "high fives" the other monkeys as the player passes by them. There is a "punk monkey" that will be followed every few monkeys, which high five off-beat.
In the sections of Board Meeting, instead of a woman assistant there is a small female monkey wearing glasses and a small pink dress. Instead of saying "One, two, three!" the monkey says "Oo-ookii!".
Before the last ball is thrown in Exhibition Match, The curtain in the middle of the arena rises to reveal a monkey, who is catching the pitcher's baseballs and dropping the to Slugger.
Monkeys made a cameo in Warioware Smooth Moves and Game & Wario, as both series had the same creators.