Experiment 400 was the 400th genetic experiment created by Jumba with Hämsterviel's funding. She was designed to control all of Jumba's other experiments. 400 and the other first 624 experiments were deactivated and smuggled to Earth by Jumba during his mission to capture Experiment 626.
All of the experiment pods were released and scattered across the island of Kauai.
At some point, 400 was presumably activated, captured, tamed and named Precious.
The first 624 experiments, including Precious, were rounded up by Leroy and taken to a stadium to be destroyed. However, Lilo, Stitch, Jumba, Pleakley, Reuben and Gantu arrived before the experiments could be destroyed.
Precious participated in the following battle between the experiments and the Leroy clones.
The Leroys soon gained the upper hand in the battle, but were defeated when Lilo, Stitch, Reuben and several other experiments performed the song "Aloha ʻOe", which caused the Leroy army to shut down due to the original Leroy's fail-safe.
Precious can control all other experiments by using her eyes. She has mind control, and can control the male species via hypnotism.
Her flaws are extreme heat/volcanoes, which can neutralize her.
- Her name, powers, and neutralization procedure are based on the One Ring from The Lord of the Rings.
- Like Link, Precious has red eyes instead of black ones like most of the other experiments.
- Precious' pod color is red.