"Dupe" is the twenty-eighth episode of Lilo & Stitch: The Series. It aired on December 29, 2003.
Lilo hosts a slumber party, but none of her classmates from hula school come. When she finds an experiment that creates duplicates, she tries to clone herself so that she can have her own friends. Stitch saves her, but is cloned instead. Stitch is weakened by the duplication when his strength is divided among all the clones. Gantu is now able to use several experiments to capture Stitch. Lilo tricks Gantu into using Dupe to turn his few experiments into an army and then combines the Stitches back into one full-strength Stitch.
- 033: Hammerface
- 344: Dupe
- 501: Yin
- 502: Yang
- 513: Richter
- 520: Cannonball
- 544: Thresher
- 609: Heat
- 617: Plasmoid
- 625: Reuben
- Moral: It's not the quantity of friends you have; it's who they are that matters.
- According to Gantu's past, his father was authoritarian, and it's because of this that he grew up lonely and with no friends. His father also told him to never trust people and to avoid them. Additionally, he revealed that he was often excluded from his peer groups' parties by the age of 12 and had braces at 13.
- Ironically, in "Frenchfry", Gantu is revealed to have college friends of his alien species when Reuben took the liberty of inviting them over.
- Hammerface, Thresher, Heat and Plasmoid are some of the few known experiments named by someone other than Lilo.
- Despite having all of Stitch's powers, Reuben suffered painful-looking injuries after he took a beating from Gantu's four henchmen experiments, most likely because he is too lazy to use his powers.
- When Stitch rolls into Hammerface, he uses Cannonball's ball form in Leroy & Stitch.
- Hammerface is Experiment 033. However, in Stitch! The Movie, he is called 124, most likely due to Jumba's untidy database.