Myaxx

Myaxx, a Chimera Sui Generis, and a member of the DNA Force Group, serves as Azmuth's assistant. She's notable for being from the same species as Ben's archenemy, Vilgax.

Appearance
In the original series, Myaxx was very similar in appearance to Vilgax before his accident with Xylene's ship, to the point Ben confused her with him. However, she had the Chimera Sui Generis mark of beauty on her main tentacle, and was leaner.

In Alien Force, she's given a more feminine appearance, with fewer facial tentacles and a leaner body.

Backstory
Myaxx originally was working as an assistant for Azmuth, the creator of the Omnitrix. She proved to be devoted to him, having helped him in collecting DNA from various alien life forms for the Omnitrix(including the ones for Wildvine and Ghostfreak), as well as creating his hiding place one planet Xenon. However, since Azmuth refused to give her the credit she deserved, she eventually walked away from him, and, as revenge for Azmuth's disrespect towards her, left her own genetic signature in the Omnitrix and erased his. She also sold the cloaking technology she and Azmuth developed to hide Xenon to the Speroid Pirates which resulted in her incarceration on Xenon by the Galactic enforcers.

Ben 10
Myaxx was first introduced in Secret of the Omnitrix, where Ben, Gwen, and Tetrax found her in the prison on the planet of Incarcecon(she was incarcerated for trying to sell the cloaking technology she designed to the Sphoeridian pirates). Confusing her for Vilgax, Ben attacked her as Upchuck. After the mistake was cleared, she told them she was the creator of the Omnitrix so they would free her from Incarcecon. Once she had escaped, she told them the truth, but agreed to help them finding Azmuth. She also provided Ben with a device that sent the destructive blasts coming from the Omnitrix right back to it, so no one around would be harmed.

On Xenon, Myaax helped- despite her cowardice- Ben and Tetrax to fight Vilgax's army. After Ben defeated Vilgax as Way Big, Azmuth offered her to be his assistant again. Though he admitted he wouldn't be able to treat her better than before, she agreed and came back with him, as she prefered that to going back to Incarcecon.

Ben 10: Alien Force
Myaxx reappears briefly at the beginning of The Final Battle: Part 1 to tell Azmuth that Albedo has stolen the Ultimatrix. Her look is completely changed, giving her a more feminine appearance. She also looks slightly taller.

Personality
Though she's from the same species than one of the most cruel and dangerous alien warlords in the Ben 10 universe, Myaxx is ironically, portrayed as a coward who would gladly try to run away if she had the chance. In an argument with Ben, she described herself as "a selfish and self-centered being". However, she showed some concern about the universe blowing up, and was able to overcome her cowardice in order to fight Vilgax's army.

Powers and abilities
As a Chimera Sui Generis, Myaxx possesses superhuman strength and endurance, making her a naturally good fighter, even though she dislikes using these abilities. She was able to defeat Ben as Upchuck, and was seen tearing apart Vilgax's drones with her bare hands.

In addition to her strength, Myaxx is an intelligent and skilled scientist, who helped Azmuth in creating the Omnitrix and so knows how to use it to some extent.

Trivia

 * During the movie Ben 10: Secret of the Omnitrix, Myaxx show at random times that she likes Tetrax, when Ben said to her that was her fault of Gwens' apparent death, she quickly hugged Tetrax, also when she mentioned that she was useless, Tetrax declined that, saying that she was a valuable ally.
 * Ben confused her for Vilgax.
 * She appears to be aware of her own selfishness, admitting in an argument with Ben saying "I am a selfish & self centered being."
 * With her selfishness and rude behavior, it is believable that she was in the Incarcecon prison planet.
 * In Secret of the Omnitrix pop-up, it says she was put on Incarcecon for selling cloaking technology to Spheroid pirates.
 * Despite her years of working with him, Myaxx had no idea that Azmuth was a Galvan outside of his suit.