Yang

Yang, A.K.A. Experiment 502, is an illegal genetic experiment created by Jumba Jookiba. He is designed to attack by spouting balls of lava. His one true place is creating a new island with Yin. Yang is voiced by Frank Welker.

Bio
Experiment 502 was the 502nd genetic experiment created by Jumba with Hämsterviel's funding. He was designed to spout lava from his back.

502 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 502's pod landing in a crack in the ground in a mountain road.

Lilo & Stitch: The Series
When a passing man poured water into his jeep's burnt-out engine, the water flowed out, into the crack and onto 502's pod, activating him. 502 then erupted to the surface and set out.

While crossing a road in front of a jeep, when the jeep's driver scolded 502 to get out of the way, the angered experiment destroyed the jeep.

502 later entered Kokaua Town and went on a rampage, destroying everything in sight. Stitch jumped onto one of 502's back spouts to try and stop the latter, but 502 simply blasted him off and most likely continued his rampage.

Due Stitch's lack of teamwork with Lilo, they had a rift over who was better at capturing experiments, which ended with Stitch joining up with Jumba and Lilo joining up with Pleakley.

Later, while 502 was scratching himself, he was ambushed by Gantu and trapped in a net. However, 502 was able to escape by simply using his lava to melt through the net.

502 was later chased by Jumba and Stitch through a jungle, but the two failed to capture the former. Experiments 501 and 502 then met for the first time. However, they were ambushed and captured by Gantu before they could make physical contact.

While returning to his ship with the two captured experiments, Gantu fell for a trap laid by Experiment 625, allowing 501 and 502 to escape.

When Lilo later tracked 502 down, the latter attacked Lilo with fireballs. However, Lilo was able to block off 502's attacks long enough for Stitch to immobilize 502 via anti-heat foam.

501 and 502 were then rehabilitated, named Yin and Yang, and given a one true place using their combined powers to create a whole new island.

Yang reappeared in "Elastico."

In "Houdini," Yang was one of the audience for Stitch's magic act.

In "Finder," Yang was seen playing poker with Stitch, Cannonball, Richter and Yin.

In "Dupe," Yang was one of the experiments who came to Lilo and Stitch's slumber party wearing pajama pants and bunny slippers. However, he was forced by Pleakley to leave due to his destructive behavior.

In "Angel," Yang was one of the experiments who Angel reverted to evil using her song. Yang and the other rehabilitated experiments attacked Stitch aboard a ship, but Angel turned them back to good before they could finish Stitch off. Working together, the experiments were then able to successfully escape the ship.

Yang reappeared in "Slugger" as part of Lilo's baseball team.

In "Ace," when the CEO of EGO arrived on Earth to decide whether or not Jumba was still evil, Yin and Yang posed as mutant creations as part of a hoax to fool the CEO.

Leroy & Stitch
Yin and Yang were seen early in the movie as Lilo was making her rounds with Scrump to make sure all the experiments were happy in the one true place they belonged.

The first 624 experiments, including Yang, 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.

Yang participated in the following battle between the experiments and the Leroy clones by shooting balls of lava at the Leroys.

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 failsafe.

Personality
Yang was shown to be short-tempered and hotheaded before his rehabilitation. He is also shown to not really care what others want him to do.

An experiment of few words, Yang is a rather single-minded being. He will focus only on what's right in front of him, paying little heed to anything else going on around him – however, this isn't to say that he's stupid. Rather, this demonstrates something of an overconfidence in his own powers, as Yang believes them more than adequate to handle any threat. Yang has a bit of a temper as well, and – once he masters speaking English more – picks up a tendency to be boastful. However, he would defend his friends loyally – that is, if he had any other that Yin – although he doesn’t see the need for "ohana" or "cousins."

Trivia

 * Yang's pod color is blue.
 * Yang is described by the experiment computer screen as, "Experiment 502 Primary function: Lava shooter."