10x, A.K.A. Experiment 266, is an illegal genetic experiment created by Jumba Jookiba. He is designed to replicate herself. (Does so by beaming out multiple versions of herself from the glass atop her head). His one true place is as an aerial performing group.
Experiment 266 was the 266th genetic experiment created by Jumba with Hämsterviel's funding. He was designed to multply herself.
266 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 an unknown point, he was activated, captured and named 10x.
The first 624 experiments, including 10x, 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.
It is unknown whether or not 10x 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 Oe, which caused the Leroy army to shut down due to the original Leroy's failsafe.
The number of which copy is currently active is displayed on her forehead. Each multiple is able to replicate 10 times. She is able to fly and breathe fire.