Rainbow Monkeys are a plush doll franchise in the Codename: Kids Next Door universe, popular mostly with girls and very small children but well-known to kids of all ages and ubiquitous in the KND universe. They are frequently used as components in KND technology.
In addition to the various colors of Rainbow Monkeys, there are numerous special-themed Rainbow Monkeys such as "Posh Party Rainbow Monkey" and "Brave-In-The-Face-Of-Certain-Doom Rainbow Monkey". There also exists numerous spin-off media, including multiple television series, and two theatrical movies. The Rainbow Monkey Song is frequently heard when they appear.
Numbuh 3's the most notable fan of the franchise, owning countless Rainbow Monkey items and is extremely protective of them. In the series finale, it's revealed that she becomes the head of the Rainbow Monkey Corporation as an adult, and, despite her love of the dolls, the first thing she did as the head of the company was get rid of an amusement park that focused on potty-training (she claimed it was mostly to get rid of the smell).
Also to be noted is that Numbuh 4's known to hate them and once called them "stoopid" (stupid).
The Real Rainbow MonkeysReal (living) Rainbow Monkeys exist in the KND universe, found on Rainbow Monkey Island. Unlike the dolls, these Rainbow Monkeys more greatly resemble real world monkeys but nonetheless friendly. The creatures of Rainbow Monkey Island change fur color, following every color of the rainbow and the color pink. It appears that the color shifts quicker during times of stress or extreme emotion. Most of the Real Rainbow Monkeys are played by Dee Bradley Baker, but Rainbow Monkey Kong is played by Frank Welker.
- The general concept of Rainbow Monkeys parodies Care Bears and Teletubbies.
- A real Rainbow Monkey doll was used as a prop in Operation: C.L.U.E.S. during the "dramatization" segment.
- In the end credits of Operation: S.A.T.U.R.N., we see that Numbuh 1 secretly owns a blue Rainbow Monkey doll.
- Rainbow Monkey Cereal (also called 'Rainbow Munchies') is the most popular cereal in the world of Kids Next Door, even enjoyed by villains--except for the oral-health obsessed Knightbrace, who attempts to destroy the last box of Rainbow Monkey cereal at the Villain Supermarket, and was beaten up by everyone at the market who were fighting over the box.