Identical twin sisters of Asian descent with long black hair.
"Night of the ZinjaEdit
The Zin Twins, real names Anaya and Melana, were the identical twin daughters of the infamous Dr. Napoleon Zin. They were unswervingly loyal and dedicated to their father, and, after his death, sought revenge against Dr. Quest and his family. To this end, they had their scientist Dr. Hatani design and build robotic assassins, three in all. The first "Zinja" was sent to steal a momentum-increasing invention of Dr. Quest's, but the thief was unknowingly stopped by Race Bannon. Race then impersonated the destroyed Zinja and reported back to Anaya and Melana, who, thinking the mission a success, dispatched the second Zinja to assassinate the President of the United States.
However when Jonny Quest tried to contact Race via the comlink he still wore, the Zin Twins overheard and ordered Dr. Hatani to stop him. Race easily defeated the scientist, but had a tougher time with the third, partially complete Zinja. However Race was able to trick the Zinja into accidentally destroying the computer which controlled the robots, deactivating both the one in the Twins' hideout as well as the one sent to kill the President.
After this, Hadji and Jessie Bannon arrived and fought Anaya and Melana in hand-to-hand fighting and (rather improbably) defeated the two grown, highly-trained women. After this, Dr. Zin himself appeared, having faked his own death to test his daughters' ability to run his empire without him. He chided them for their failure
The Zin Twins and Dr. Hatani escaped aboard their helicopter.