El Fin, A.K.A. Experiment 611, is an illegal genetic experiment created by Jumba Jookiba. He is designed to make the universe implode when Jumba says the password, but fortunately, Jumba forgot it. His original name was Doomsday, but this was changed due to a copyright issue.
611 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.
The first 624 experiments, presumably including El Fin, 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 El Fin 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 ʻOe", which caused the Leroy army to shut down due to the original Leroy's fail-safe.
El Fin is a purple bat-like experiment about three feet tall with two blue jewels for eyes with no legs, a red jewel on his chest, a reptilian face with a wide mouth and round nose.
- His name "El Fin" means "The End" in Spanish, as in "The end of the universe".
- El Fin's pod color is blue.
- El Fin is described by the experiment computer screen as, "Experiment 611. Primary function: Ultimate super weapon".