Barrel of Monkeys

The Barrel of Monkeys are a real-life toy by Milton Bradley seen in the Toy Story series. It consists of a colored barrel (Andy's is yellow) containing twelve red monkeys. The goal of the game is to pick up the most monkeys by creating a chain with their hooked arms.

Toy Story
In the first film, they are first seen being used by Andy's toys as they try to save Buzz Lightyear after falling out of the window of Andy's room in Toy Story.

The monkeys appear again at the end of the film in Andy's room engaging in the Christmas festivities with the rest of Andy's toys, hearing what presents Andy receives for Christmas from the Green Army Men.

Toy Story 2
In the second film, they appear in a scene where Andy has Hamm, portraying as "Evil Dr. Porkchop," give Woody the choice of "Shark" or "Death by Monkeys" for a captive Bo Peep. They are later seen at the very end of film joining the rest of the toys to watch Wheezy sing You've Got a Friend in Me.

They later appear in one of the outtakes, harassing Mr. Potato Head, when Mrs. Potato Head suggests that he take monkey chow with him in his parts storage on the journey to save Woody.

Toy Story 3
In the third film, they are seen in an opening scene during Andy's play scenario that takes place in the wild west. Hamm, as Evil Dr. Porkchop controlling his ship, activates the button labeled "Death by Monkeys," which unleashes a barrel that explodes when it hits the ground, sending thousands of monkeys scattering in all directions. The monkeys grab Woody, Jessie, and Buzz, holding them hostage, as Mr. Potato Head, whom Andy portrays as the villainous One-Eyed Bart, prepares to finish them off.

Later, when Woody gathers all the toys remaining, none of the monkeys are seen. Since Barrel of Monkeys is actually a game, the monkeys may have been put in the attic.

Hawaiian Vacation
The Barrel of Monkeys were seen in the Toy Story Toons episode, Hawaiian Vacation. In the short, Bonnie was seen to have three red barrels. Each barrel was being played by an Alien as a drum, while the monkeys danced as they put on a Hawaiian show for Ken and Barbie.

Trivia

 * Andy's Barrel of Monkeys is based off the '90s variety.
 * It is a possibility that the Barrel of Monkeys were given to Andy for his birthday in the first Toy Story film as they were not seen before until Rex was trying to help Buzz when he was pushed out of the window.
 * Aliens hanging in the same fashion as the Barrel of Monkeys appear in Buzz Lightyear's Laser Blast.
 * There is approximately 1.4 million Monkeys in the "Death by Monkeys" explosion in the Western opening of Toy Story 3.