A green, skinny Stitch look-alike with a spiky yellow Mohawk and two prominent fangs jutting from his lower jaw. He has all of Stitch's powers and is jealous of all the attention Stitch gets. In the Playstation 2 game Disney's Stitch: Experiment 626, he steals the DNA that Stitch collects for Jumba, mutating into a stronger form. The plot of this game has since been retconned from canon continuity due to the events depicting Stitch being apprehended immediately after his creation in Lilo & Stitch 2: Stitch Has a Glitch. However, 621 could still have the same physical appearance and personality. He is both very physical and well-equipped. His weapons include Jet-Pack, Grapple-Gun, rocket-launching Big Gun, and Freeze Gun. He also has the strange ability to mutate when power is charged at most extreme. He also dresses in a brown uniform. He is voiced by Frank Welker.