Houdini, A.K.A. Experiment 604, is an illegal genetic experiment created by Jumba Jookiba. He is designed to turn entire armies and weapons invisible with a blink of his eyes, but had a flaw in his program that made him a coward on the battlefield. His one true place is as a Hollywood star magician, but his actions have promoted him to a shark tank attraction, making sharks disappear to entertain crowds.
Houdini is a very timid and easily frightened experiment. He is shown to be easily scared by everything, suggesting he has panphobia. He is also easily intimidated and startled by loud noises. It took a tremendous effort for him to leave show biz to go help out his cousin Stitch when he was in Okinawa, and even then he typically stays invisible 95% of the time.
Experiment 604 was the 604th genetic experiment created by Jumba with Hämsterviel's funding. He was designed to render entire armies and weapons invisible, but due to being cowardly, he instead kept turning himself invisible and fleeing the battlefield. 604 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.
On a small outdoor stage, Stitch and Pleakley practiced a magic act in front of Lilo, Nani, Jumba and a few experiments for Mertle's upcoming half birthday, but Stitch kept bungling the act with his failed tricks.
When Lilo realized that Stitch was having trouble, she asked Jumba if he had any experiments that could help with Stitch's magic act. Jumba then took out 604's pod, but warned that 604 had cowardly habits.
604 was activated by Lilo and named Houdini, who promptly panicked and made himself invisible until Lilo pacified him. She then trained him to turn things invisible upon hearing "Alakablooe," and vice versa upon hearing "Alakazoo" with a blink of his eyes.
During Mertle's party, Houdini secretly helped Stitch out with his magic act. However, the former was eventually caught in the act by Mertle, who photographed Houdini. The camera flash spooked Houdini, causing him to turn Stitch and numerous other things invisible, including himself.
Before Houdini became invisible, Gantu, who was looking for the experiment, spied on Stitch's magic act and spotted Houdini. However, Houdini escaped in fear when Gantu crashed the party. Later on, Mertle visited Lilo's house and condemned her for being a fraud before revealing the photo taken of Houdini.
To make matters worse, Mrs. Edmonds booked Mertle's aunt and her staff to witness Stitch's magic act. Lilo knew that Stitch couldn't possibly do magic without Houdini's help. While Stitch was invisible, Lilo adorned him in different ways so that she could still see him before they searched for Houdini.
Later, Gantu pursued an invisible Houdini through the jungles of Kauai wearing special heat goggles, but the latter was able to slow Gantu down by turning palm trees and other obstacles invisible.
Before long, Houdini bumped into an invisible Stitch. The collision caused Lilo to touch what she thought was Stitch (but was actually an invisible Houdini). Gantu captured what he thought was Houdini (but was actually an invisible Stitch), which he took back to his ship.
Later, when Lilo began to get suspicious of whom she thought was Stitch, Houdini made himself visible again. Lilo then realized that Gantu must have grabbed Stitch by mistake. When Pleakley scolded Houdini, the latter turned invisible out of fright and fled.
Meanwhile, an invisible Stitch began trashing stuff inside Gantu's ship. Gantu and Experiment 625 grew suspicious, but then Gantu fired his plasma gun repeatedly in an attempt to subdue the invisible experiment. After a brief struggle, Stitch managed to escape the ship and reunite with Lilo. Additionally, she and Stitch recaptured Houdini after a long chase.
While Pleakley was being booed by the staff for stalling them with his promised magic act, Lilo, Stitch and Houdini arrived just in time. Houdini then made the old lighthouse disappear, much to Pleakley's relief. The crowd cheered, although when Lilo revealed Houdini, the people became intrigued and began taking flash photos of the experiment, causing him to make everything on Kauai disappear.
Shorty after, Houdini was found a one true place in Hollywood as a star magician.
Houdini reappeared in "Snafu", performing a magical act to a crowd.
The first 624 experiments, including Houdini, 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.
In the following battle between the experiments and the Leroy clones, Houdini evaded attacking Leroys by turning himself invisible.
However, 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 `Oe", which caused the Leroy army to shut down due to the original Leroy's fail-safe.
- Houdini was named after the famous Hollywood magician, Harry Houdini.
- Houdini's picture in Lilo's cousins scrapbook is the same picture Mertle took of him in Houdini's debut.
- Houdini's pod color is yellow.
- Houdini is described by the experiment computer screen as, "Experiment 604. Primary function: Invisibility generator."