Android 19 is a large android with completely white skin and was created by Dr. Gero in order to kill Son Goku as revenge for destroying the Red Ribbon Army. He first appeared alongside Android 20 on an island 9 kilometers southwest of South City where they both started wreaking havoc before being intercepted by Goku and his allies, who had been warned of their appearance by Trunks. He has the ability to absorb people's energy through his hands to give himself the upper hand in combat.
In "Dragon Ball Full Color: Artificial Humans & Cell Arc Volume #03," Akira Toriyama revealed that: "The model for No. 19 was a doll that was displayed in the command center of an enemy base. Way back when, Dr. Gero took it back with him as a war trophy."
Though not particularly strong, he managed to beat Goku in battle due to the heart virus that he had contracted. 19 almost killed Goku by draining him of his energy, but he was interrupted by Vegeta who proceeded to beat him with little effort. Vegeta then transformed into a Super Saiyan and started taunted him mercilessly and asked him if androids feel fear. After 19 had his energy absorbing hands torn off by Vegeta, he tried to flee in fear only to be vaporized by Vegeta's "big bang attack" leaving nothing but his head behind.
In Dragon Ball GT, everyone escapes from Hell and Android 19 is among them. He is easily defeated by energy blasts from Son Goten and Trunks, the son of Vegeta.