Experiment 628 is an illegal genetic experiment created by Jumba Jookiba, and the second experiment to be created on Earth with limited alien technology. It was created shortly after Experiment 627. After Stitch defeated 627, Jumba locked 628's pod away in a vault.
- In promotional material for Leroy & Stitch and on Japanese and Disneyland Paris merchandise, Leroy was referred to as Experiment 628. However, this is false, as he was only called Leroy in the film and is the evil doppelganger of Experiment 626.
- 628's pod color is blue.