Dr. Zin was a power-hungry scientist who was the sworn arch-enemy of Dr. Benton Quest, and, by extension, his son, Jonny. He would stop at nothing less than world domination, often attempting to steal his rival Dr. Quest's inventions and ideas for his own use. He had two daughters, Anaya and Melana, who became known as the "Zin Twins." Dr. Zin is the main antagonist of the original Jonny Quest animated series.
The Original and New Adventures
Zin primarily operated behind the scenes, relying on various operatives and machines to do his bidding so he would not get his hands dirty. He first tried to create synthetic gold to become wealthy, but his operation in India was stopped by the Quests. He then attempted to use a gigantic spider-like robot probe to attack a military base and steal the designs for Dr. Quest's para-power ray. The robot was destroyed by the experimental para-power ray before it could return to Zin with the plans.
Zin also kidnapped Race Bannon and replaced him with a double so the double could steal a Thai drug created by Quest to enhance astronauts' alertness while in space, but Jonny and Hadji suspected "Race" and enlisted the aid of Jezebel Jade to expose the impostor and rescue the real Race. After this, Zin hatched a scheme to sell a weapon of mass destruction out of a dormant volcano in Haiti, using trickery and special effects to make it seem as though the volcano was active to keep people away. Dr. Quest and his team foiled the plan and the local military destroyed the volcano, however Zin survived because he was transmitting from elsewhere.
The Golden Quest
When next encountered by the Quests, this time with Benton Quest's wife Rachel, Zin was dying of a debilitating illness that required him to be hooked up to an oxygen tank. In an effort to save his own life, Zin, working out of an active volcano in Peru, sought to clone himself, but the clones were imperfect, deformed mutants. To perfect the cloning process Zin hired Dr. Victor Devlon to help him create pure gold to inject into the clones to stabilize their metabolic processes. When the Quests attacked the base Devlon stole Zin's work on creating synthetic gold and fled, while a perfected clone of Zin kidnapped Rachel Quest and attempted to escape with her, only for their helicopter to crash into the erupting volcano, killing both.
The real Zin enlisted the aid of Jezebel Jade by kidnapping Jessie Bannon, Jade's daughter with Race Bannon, forcing her to use a synthetic gold mask to lure the Quests into a trap so they would lead him to Victor Devlon who was using Zin's own synthetic gold process to try and make himself rich. Upon finding Devlon in Italy, Zin killed him and took back his research, and also kidnapped Race Bannon, taking him to a desalinization plant in Australia where he intended to use Race's genetic code to make his next batch of clones perfect. The Quests attacked and defeated Zin's deformed clones, and saved Race, destroying the plant in the process. Zin tried to escape in a one-man submarine but was killed when debris fell on the vessel and prevented him from exiting before the entire building exploded.
One semi-perfected Zin clone survived however, and washed ashore further down the beach.
The Cyber Insects
This clone, possessing all of the original Zin's memories, hatched Zin's grandest scheme yet. Commanding a weather satellite from a cloaked asteroid base in Earth's orbit, the clone, still suffering from the same debilitating disease as the original Zin, sought to drastically alter Earth's weather to leave the planet open for invasion by his army of genetically engineered giant insects - Formicoids, Platinoids and Hymenoptoids. He also eventually created a fourth new breed, the Assassinoids. He was once more thwarted when the weather satellite was turned against the asteroid, heating it up until it exploded, but Zin got away in an escape craft.
After this, Zin was believed dead.
The Real Adventures
However he at some point either created a perfect clone of himself, or finally was cured of his disease, for by the time Jonny, Hadji and Jessie were all young adults, Zin returned with a vengeance, assisted by his daughters Anaya and Melana. He held a NASA space station hostage and also reused his original robotic spies in an effort to kill the Quests once and for all. After that failed, he and his daughters enlisted the help of Dr. Hatani to created robotic ninjas called Zinjas to kill the Quests. Once more he was bested by his old enemies, and, swearing revenge, Zin escaped with his daughters and Dr. Hatani, vowing to return.
Tom and Jerry: Spy Quest
Tom and Jerry have a relaxing day at the beach until Jonny Quest, Hadji and Bandit arrive. They have to help stop an evil cat army from stealing Dr. Benton Quest's newest invention for him.