The Androids
Android #8
An android created in Dragon Ball that became good and made friends with Goku.
Android #16
One of the androids that first appeared in the DBZ Android saga. He didn't
exist in the future. #16 is not an evil android and prefers nature to fighting.
He was reprogrammed by Bulma and Dr. Briefs to join the Z warriors in the
Cell Game. He tried to sacrifice his life by self destructing in an attempt
to kill Perfect Cell, but Bulma had removed his bomb and he couldn't self
destruct. Cell killed him and stepped on his head.
Android #17
#17 is the twin brother of #18 and also appeared in the DBZ Android saga.
They were the main villains in Trunks' future. In the present timeline, they
revived #16, but were then absorbed by Cell. After Cell had been killed in
the Cell Game, #17 went to live by himself in the woods. In DBGT, he fused
with Artificial 17 who was made by Dr. Gero and Dr. Myuu in Hell to make Super
17 who was killed by Goku.
Android #18
#17's twin sister. Absorbing her in the Android saga made Cell become Perfect.
In the Cell Game, Gohan punched Cell and he regurgitated her, changing back
into his second form. After Cell had been killed, Krillin used the other wish
with the Dragon Balls to make #17 and #18 human again. In the Buu saga, Krillin
and #18 were married and had a daughter called Marron.
Android #19
This android did not exist in the future either. It is partners with #20 and
they both have special red dots on their palms that able them to absorb people's
energy. When Trunks came back for the second time, he saw the Z warriors were
fighting these two instead of #17 and #18. #19 was killed by Vegeta.
Android #20
#19 made Dr. Gero into this android. They have similar abilities in the Android
saga. #20 was killed by #17.