Monkeys are an important animal in the Monkey Island series of games, as its name suggests. In each game, Guybrush Threepwood receives some help from monkeys, both on Monkey Island itself and in other parts of the Caribbean.
When Guybrush arrives on Monkey Island, there is a grey monkey in the jungle nearby. After he is given enough bananas, the monkey will follow Guybrush around the island, staying behind in the jungle when Guybrush enters any area except the clearing where the Giant Monkey Head is found. If Guybrush pulls down the totem-pole nose that acts as a lever to open the gate to the Head, the monkey will imitate and hang from the lever, allowing Guybrush to pass. In the fourth game, it is revealed that, never having been taught to let go of the lever, the monkey held on until he starved to death, and is buried near that spot.
A running gag throughout the series, the Three-Headed Monkey makes its only indisputable appearances in the Cannibals' village. If Guybrush tries more than once to distract the Cannibals with the line "Look! A three-headed monkey!" it will appear the second time, when nobody turns to look. Later it reappears when Guybrush is waiting, alone, for the Cannibals to mix up the anti-root potion.
When Guybrush goes to break up LeChuck and Elaine's wedding at the Mêlée Island church, the figure in the bridal gown is revealed to be two monkeys, one standing on the other's shoulders. Elaine had already escaped, set the monkeys up as a decoy, and given them her ghost-vanquishing anti-root potion, but Guybrush frightens them away. Elaine goes to chase after them, leaving Guybrush to fight LeChuck alone.
A pair of grey monkeys will come onscreen and dance during the opening credits, but Guybrush repeatedly chases them away.
Jojo the monkey is brought in to play piano at the Bloody Lip Bar and Grill during Part II. Guybrush can distract the musician with a well-placed banana, pick him up, and use him as a monkey wrench to stop the flow of the Phatt Island Waterfall and reveal an underground tunnel leading to the small offshore island where Rum Rogers' Cottage can be found.
When Guybrush reaches Danjer Cove at the far side of Plunder Island and boards the Sea Cucumber, he is confronted by first mate Mr. Fossey, who orders that Guybrush be tarred and feathered. The Pirates of Danjer Cove are then revealed to be a band of monkeys under Fossey's command, with a gorilla called Captain LeChimp as the nominal leader. Guybrush adopts LeChimp's voice to convince Fossey to let the crew go. The monkeys then go to the Long John Silver Center for the Performing Arts in Puerto Pollo to watch Slappy Cromwell's performance Speare: A Theatrical Medley. They greatly enjoy his juggling acts, especially when he goes flying off the stage.
In Part 5, LeChuck mentions to Guybrush that the power of Big Whoop is finite, and alone it could not indefinitely power the Carnival of the Damned. Instead, he has combined this power with what he calls "Monkey Island's greatest natural resource": monkeys. The waving figures on the Rollercoaster of Death are referred to as being "Dynamo-Monkelectric" powered; one of them is a three-headed monkey. When Guybrush sees Wally, he mentions that he intends to free both Wally and the monkeys after defeating LeChuck, but whether he follows through on this is never seen.
When Guybrush and Elaine return from their honeymoon they are first greeted by Elaine's pet Timmy the Monkey, whom they seem to be able to understand. Later Timmy seems to go missing, one of many monkey disappearances across the Tri-Island Area; on Lucre Island Deadeye Dave laments the loss of his employee Pongo at the Palace of Prostheses, while on Jambalaya Island the absent Floppo the Bouncer Monkey has been replaced by Murray.
When Guybrush is stranded on Monkey Island, he reunites with Timmy and learns why all the monkeys have disappeared: they have come to Monkey Island, called in anticipation of some great event they do not understand but must obey. Timmy is on the beach where Guybrush lands and can be led around the island with bananas, as in the first game; he is helpful in opening a strange door in the mines. The rest of the monkeys are in or around the village abandoned by the Cannibals when they removed to Blood Island. Their leader is the Monkey Prince Jojo Jr., son of the monkey who helped Guybrush in the first game. Jojo Jr. is able to speak, a power he gained when burying his father in front of the Giant Monkey Head. Guybrush can engage these monkeys in Monkey Kombat, an ancient form of battle with a mysterious link to the Ultimate Insult. The monkeys' purpose is revealed when Guybrush activates the Giant Monkey Robot, which is operated by monkeys throughout its body. After defeating LeChuck and Ozzie Mandrill, the monkeys head off to parts unknown, leaving behind only Timmy.
- Escape from Monkey Island se anunció diciendo tener más monos que los tres primeros juntos, lo que dado el número de monos necesario para alimentar el Robot esta afimación es probablemente correcta.
- En la primera parte de The Secret of Monkey Island, la Señora del Vudú predice que Guybrush terminará en el interior de un mono gigante, pero su vaga visión se refiere a la Cabeza de Mono Gigante.