Experiment 284 was the 284th genetic experiment created by Jumba with Hämsterviel's funding. She was designed to steal the pictures 214 takes.
284 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 the unknown point, 284 was activated, captured, tamed, and named Pixel.
Pixel is a small, red experiment. She has a head that looks a lot like Stitch's, but her ears are a different shape, and her nose has an X across it. She has two arms and three claw-like legs.