Evil scientist Dr. Gero created the Androids for his own nefarious purposes. In an attempt to defeat the Z Warriors and destroy the Earth, Dr. Gero even goes so far as to turn himself into an Android.
Big and powerful, Android 16 prefers to let his muscles do the talking for him. Android 16 joins 18 in the fight against Cell.
Android 17 is a dark-haired youth with a major attitude problem. He later contributes to the threat against Earth that forces Trunks to travel back in time.
Android 17's "sister," the beautiful Android 18 has a real mean streak, but she does help our heroes make a final stand against the power-hungry Cell.
The first Android to arrive on Earth, Android 19 is a clever, overweight warrior with a love for exotic weapons.
In an attempt to become more powerful than ever, Dr. Gero commands Android 19 to turn him into Android 20. As an Android, Dr. Gero lets nothing get in his way.
Dr. Gero's most dangerous creation -- perhaps even more powerful than the Androids combined -- is the genetic nightmare known as Cell.