The Bad Guys!

Freeza:

Species: Unknown

Planet: Unknown Special Techniques: Planet Destroyer, Energy Disks(Continuesly follow the target), Freeza is one of the most evil and powerful fighters in the universe. We first see him on the planet Namek, where he is forcing the local residents to give him their Dragon Balls so he can wish for immortality. You might notice that we are using the pronoun 'he.' Even though the voice in the American version bares a striking resemblance to that of a female's, believe me, Freeza is male. Freeza is the leader of an organization known as the Planet Trade, who sells planets to customers after destroying all of the planet's inhabitants. Freeza was always paranoid that the legendary Super Saiyan would emerge among the Saiyans, so he destroys the planet Vegeta, leaving only four remaining Saiyans in existence. The four were Vageta, Raditz, Nappa, and Goku (also known as Kakarot)(There is also Gohan, but Freeza doesn't know about him). Of course, Goku becomes a Super Saiyan and defeats Frieza... or so we thought. One year later, Freeza, along with his father King Kold, comes to Earth in the form of a half robot and threatens to destroy the world. He is then decisively defeated by a mysterious youth, a Super Saiyan, by the name of Trunks.

Cell, who is actually the 21st android, is one of the strongest villains in DBZ. His name comes from the type of cells that make up all matter. He has the power to regenerate if even ONE of his cells is still intact, which he demontrates when Gokou sacrifices his life to blow him up. He also has the ability to create miniature versions of himself, called Cell Juniors, which he makes from a tube on his back. He was created by Dr. Gero as the "ultimate" killing machine, namely to kill Son Gokou. He is defeated by Son Gohan when he makes Gohan a little too angry by killing Android #16. Gohan surpasses Super Saiyan, and eventually kills him.