Android 21; created by Dr. Gero. He was completed in Future Trunks' timeline. Cell killed Future Trunks, stole his time machine, and traveled back to time to absorb Androids 17 and 18 to reach perfect form. The Z warriors defeated him, but he sacrificed himself in an attempt for a final victory by triggering the bombs in his body (Gokou teleported Cell to explode in Kaiou's planet to save the Earth), but regenerated from a single surviving brain cell. At the end, he is killed by Gohan. In hell, he allied with Freeza in an attempt to take over the Nether regions, but stopped by Gokou and Paiku-han. Later, he was upgraded by Dr. Gero and Dr. Myuu and allied with Freeza again to fight Goku, but was defeated once again by Goku.