Cell (セル, Seru) is one of the major super-villains of the Dragon Ball manga and the Dragon Ball Z anime, and is the ultimate creation of Dr. Gero, designed to have all the abilities of the greatest fighters to have ever inhabited or visited Earth. The result was a "perfect warrior", possessing numerous genetic traits and special abilities. It should be worth noting that he is the only Red Ribbon Android to not have the Red Ribbon insignia on him at one point or another. It is also worth noting that he is one of the few Androids not directly created by Dr. Gero; the only others are Android 13, Android 14, Android 15, and possibly Android 8. Both Cell and Androids 13, 14 and 15's conceptions involved Dr. Gero's Super Computer.
Cell's personality changes drastically throughout the Androids Arc. He is unique among most villains of the series, being that he is quite sophisticated. As his evolution proceeds, he can be observed as having a more patient and calculating approach towards his goals. Because of his genetic composition from other warriors, he is able to psychologically manipulate those warriors and exploit their weaknesses to his advantage.
At first, Cell's desire to complete his evolution by absorbing both Android 17 and Android 18 was what fueled him. Upon reaching his final form, his eagerness to test the limits of his newfound power was what defined his character.
With each transformation, Cell's personality underwent a drastic change. Initially, Cell is completely single-minded in pursuit of his goals. Upon reaching his first transformation, he becomes far more brash and impulsive in his actions. Upon reaching perfection, Cell displays a number of traits shared by those whose cells he possesses; Piccolo's cunning, Vegeta's pride, Goku's laid-back disposition, Frieza's smugness, and the Saiyan lust for battle. Perhaps Cell's most distinguishable trait in this form is his uninhibited vanity which he shamelessly puts on display by launching the Cell Games, a "tournament" organized for the sole purpose of showing off his new found power. It can also be seen during Cell's confrontation with Gohan when he affirms his "true purpose": the annihilation of anything he considers imperfect, a category in which he places everyone and everything but himself.
In the English manga, Cell is always referred to as an "it", while in the anime (and the Japanese versions of both), he is referred to as "he." He is likely described that way in the English manga to emphasize the fact that he is an artificial being.
Cell is composed of cells from Goku, Piccolo, Vegeta, Frieza, King Cold, and according to the manga title page, a number of other lifeforms (in the FUNimation dub, it is also stated that he has cells from Krillin, Gohan, Nappa, and Tien Shinhan). He also possesses information on Nappa, Raditz, Gohan, Tien Shinhan, Chiaotzu, Krillin, Yamcha, and Future Trunks that was collected by Dr. Gero's remote tracking device and stocked in the Super Computer. Cell is therefore able to use their attacks (ex. Kamehameha, Regeneration etc.). His genetic composition is very much a part of his character. It is also implied that, when using these attacks, he often changes his genetic code so he could match the genetic source of his attacks, as when he was going to fire the Kamehameha at Piccolo, Gohan and Vegeta sensed Goku in the distance, with the former being near Goku at the time. In his Imperfect Form, he is clever and calculating and single-minded about achieving his Perfect Form. In his Semi-Perfect Form, he is a little more arrogant. In his Perfect and Super Perfect forms, he is extremely arrogant, he becomes very smug and he believes that every other living creature is inferior to him, and is shown to be very polite unless he loses his temper. Upon meeting Piccolo for the first time in Gingertown, Cell tells Piccolo that the computer programmed some genetic traits to be more dominant than others. He bears a strong resemblance to Frieza in all of his forms such as his tail and the talon-like feet of his first form, and in his perfect form, his face resembles Frieza's first form. He can also revert back a few stages at will if necessary, as evidenced when Cell reverted back from his Imperfect form to his Larval form in order to use Trunks' Time Machine.
Cell was designed to have the ability to absorb any biological mass by stabbing his victims with his tail. This process, called "bio-extraction," drains all the organic mass out of the target from the inside out. This attack increases Cell's power, the exact amount depending on the victim's power level. Cell was designed to absorb Dr. Gero's other androids (Android 17 and Android 18) whole, integrating them into his systems. Each time he absorbs an android, he evolves into a more powerful being, however he cannot absorb completely mechanical Androids such as Android 16.
Upon assimilating both Android 17 and Android 18, he gains the ability to asexually reproduce, creating blue, child versions of himself, called "Cell Juniors"
Apparently, he may also be able to change his voice to one of his other forms at will, as Perfect Cell used his Imperfect form's voice during his announcement of the Cell Games in "The Doomsday Broadcast" when explaining that he was the "creature from Nicky Town". He is also able to manipulate his voice, changing it to someone he absorbed. As when Semi-Perfect Cell changed his voiced to 17's to try to convince 18 to merge with the bio-android.