Android 18

From Multiversal Omnipedia

Android 18 was the sister of Android 17, one of a pair of twins converted into androids by Dr. Gero. Like her brother, 18 became an incredibly powerful fighter, but also became rebellious. 18, along with 17, was placed in stasis by Gero until he was endangered by the pursuing Z Warriors; he freed them, hoping to coerce them into helping him with the threat of putting them back in stasis, but they killed him and set out on their own (with Android 16) to find and battle Goku. Along the way, 18 fought a newly Super Saiyan Vegeta and humiliated him thoroughly. 18 expressed a bit of affection towards Krillin, which he later reciprocated strongly.

After Cell absorbed 17 and transformed into his second stage, 18 threatened to self-destruct rather than be absorbed; however, at Tien and 16's urging, she went into hiding. Krillin found her; he had been given a device that could deactivate her, but refused to do so. Cell managed to absorb her when given allowance to do so by Vegeta, and ascended to his Perfect form.

18 was freed from Cell's body by a devastating blow from Super Saiyan 2 Gohan, and Krillin later had Shenron remove her and 17's self-destruct devices. Touched, 18 later married Krillin, and they had a daughter, Marron.

Android 18 (who received some limited training from Krillin, although she didn't need it) participated in the 25th World Martial Arts Tournament, and "lost" to Hercule Satan (after securing a substantial payoff). 18 was turned into chocolate and eaten by Buu, but she was resurrected by the Namekian Dragon Balls.

Dragon Ball GT

18 settled down as time went on, but found herself forced to battle her maddened brother when he came under the influence of Artificial 17 and slew Krillin. She regretfully helped Goku destroy Super 17.

Alternate Timelines

In Trunks' timeline, 18 (along with 17) was the scourge of the planet (although they were weaker than those in the main timeline.) She was finally destroyed by Trunks after his return from the main timeline's past.

Movies

In an attempt to collect the money owed her by Hercule, 18 was pulled into battling Bio Broli.