Legend says that whoever is wearing the amulet becomes the Monkey King. The amulet is on display at the Forbidden City Museum in China. Monkey Fist desires the Amulet so he can be the next Monkey king in the new era. He attempts to steal the amulet from the Museum. Kim Possible is waiting for Monkey Fist at the museum when he attacks. During the battle, the amulet is accidently tossed around Kim's neck. The amulet bonds with Kim in the form of a green monkey shaped tattoo on her neck. The Amulet slowly turns Kim into a monkey. It is unknown what happens to the amulet after Kim is separated from the Monkey DNA.
According to the ancient text, there is only one way to part someone from the amulet, a very painful way.