Ace

Ace, A.K.A. Experiment 262, is an illegal genetic experiment created by Jumba Jookiba. He is a superhero experiment. His one true place is as the local superhero, and helping reform Jumba. Ace is voiced by Jeff Bennett.

Bio
Experiment 262 was the 262nd genetic experiment created by Jumba with Hämsterviel's funding. He was designed to be a pure evil experiment, but was instead a pure good superhero, much to Jumba's embarrassment.

According to Reuben, Jumba kept 262 locked in the basement when friends came over.

262 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, with 262's pod landing in a bush by a house.

Lilo & Stitch: The Series
When a fire started in the house, a fireman accidentally drenched the nearby bush with water from his fire hose, activating 262.

When 262 heard that the family's kitten was trapped inside the burning house, he heroically rushed in and rescued the kitten from the fire by jumping out a window with the kitten, using a bedsheet as a parachute. 262, named Ace, then put out the fire using the fireman's fire hose, and found his one true place as a local do-gooder.

Leroy & Stitch
The first 624 experiments, including Ace, were round 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 Ace participated in the following battle between the experiment 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 `Oe, which caused the Leroy army to shut down due to the original Leroy's failsafe.

Trivia

 * Intriguingly, Ace's number is the opposite of Stitch's, and while Stitch was originally pure evil, Ace was always pure good.
 * Ace is one of the few experiments that was not evil before he was found by Lilo and Stitch.