Cell is a ultimate creation of Dr. Gero. He has designed to have all of the abilities of th greatest fighters have ever inhibited or visited Earth. The result was a "perfect warrior" possessing genetic traits and special abilities. Cell has absorbed 17 and 18 to achieve his perfect form. When he is selfdestructed himself in Cell Games, Cell achieved his Super Perfect Form. Afterwards he was defeated by Teen Gohan and in hell along with the rest of the DBZ villains.
Cell in his perfect form.
Imperfect Form Cell
Semiperfect Form Cell
Cell killed many people, mostly like Android 16 and Future Trunks.