Ultimate Marvel: Earth-2/Cassandra Lang

Ant-Girl (Cassandra "Cassie" Lang) is a fictional major character and superheroine appearing in Ultimate Marvel: Earth-2.

Early life
Cassie was born in Brooklyn, New York City, raised by her parents Scott Lang and Hope Van Dyne. She grew up living life like any ordinary child, but displaying a great admiration for superheroes. This motivated her parents to become superheroes themselves by donning their versions of Hank Pym's Pym Particle suits (with Scott becoming the new Ant-Man after Hank Pym and Hope becoming the Dragonfly). Cassie also became best friends with Katherine "Kit" Renner, who shared Cassie's passion for superheroes (most closely Captain Marvel).

Becoming Ant-Girl
After enjoying her 10-year birthday party (which was also attended to by Spider-Man as a surprise special guest), Cassie had a moment with her father at night. From Scott, she earned one last special gift: a Nanotech wrist device containing Pym Particles. Excited and grateful, Cassie vowed to do what must be done to be a heroine like her parents and other known heroes in the world.

Next day, she soon designed her suit through the device's panels and begun practicing for her career as Ant-Girl. After one month of training, Cassie started her heroic career with common civilian acts (such as helping a little girl get her kitten out of a tree and stopping a robber from assaulting an old man). Then, she begun to take on her first foe: the outlaw Whirlwind, who was at the time robbing from Roxxon and bullying J. Jonah Jameson's son Rowley (also known by public as the superhero-wannabe Captain Ultra). While Whirlwind was taking on Captain Ultra pretty easily, Ant-Girl shrunk through Whirlwind's armor and begun attacking his soft skin, with Whirlwind just screaming in pain, not knowing what hit him until Cassie ejected from his suit and revealed herself.

Just as Whirlwind teased that she would not stop a bomb which he implanted beneath a nearby school with children and pulled its trigger, Ant-Girl just replied she already took care of that; she had found and shrunk the bomb into miniature portions and hidden it inside Whirlwind's pants. The bomb soon exploded and caused great pain in Whirlwind's groin as he screamed like a girl to both Ant-Girl and the crowd's amusement. Ant-Girl soon earned the appreciation of the citizens (including her parents, who were watching from the distance), though Captain Ultra just felt constant humiliation of being "up-staged by a little girl". Seeing how much being a hero is very enjoyable, Cassie embraced her new calling with delight, though she also had to balance it with her normal life as a normal citizen and school student.

Along the way, Ant-Girl also earned herself her own arch-nemesis Yellowjacket (who happens to be Cassie's aunt Janet Van Dyne's rival in college Rita DeMara) after teaming up with Spider-Man in stopping her and Doctor Octopus from their evil intentions against Cassie's babysitter Cindy Moon, whose Inhuman DNA transformed her into the Shadow Widow. She also had the attention and mutual respect of other young heroes such as the rest of Spider-Man's friends (including the numerous girls who viewed her as a little sister and treated her very gently), and joined them in their training under the tutelage of hero veterans (like Shang-Chi, El Diablo, among others).

During her adventures, Cassie also obtained the Quantum Key, a new hightech device which allows the user to access the Quantum Realm. She progressively begun discovering secret features within the Realm, including the existaance of Star Tubes, extra-dimensional vortexes which allow the user to travel through anywhere in space at his/her will. While amazed with this discovery, she decided to keep that knowledge in secret from most people (except her friends and her father Scott) until the time was right.

Meeting Meta-Dino
Among other adventures as Ant-Girl, Cassie also among the humans working to contribute for Professor Charles Xavier's campaign of peaceful human-mutant coexistance. Becoming aware that mutant terrorist Erik Lehnsherr / Magneto was having plans to foil Xavier's campaign, Cassie volunteered herself to find evidences of his plans so that the X-Men would be prepared.

Using a tracker she implanted on one of Magneto's Acolytes during their direct attack in Roxxon and the Quantum Key, Cassie used the Quantum Realm's Star Tubes to infiltrate Magneto's orbiting base, the Asteroid M. There, Cassie did so by recording footage and images of Magneto's future plans for human genocide. She soon met orphaned young mutant Humberto Lopez / Meta-Dino, who proved to be different of most mutants residing in Magneto's base and did not agree with Magneto's terms about war with humans. Taking a friendly liking to him, Cassie left, but promised to come see him again some more.

After delivering the evidences to Jean Grey, Cassie kept the promise she made to Humberto and begun visiting him in Asteroid M day by day to keep him comfortable. They more time they spent together, the more they begun having grown feelings for each other. Later on, Cassie witnessed the X-Men battling Magneto and his Acolytes in Alcatraz Island. Once Beast convinced her that the battle would keep Magneto distracted enough to render Asteroid M unguarded, Cassie went there to see Humberto again. And this time, she removed the implants which would help Magneto's lackeys track Humberto and encouraged him in coming with her.

Humberto, understanding how free he was from Magneto's rules, agreed and went with Cassie through the Quantum Realm's Star Tubes. Later, after the X-Men defeated Magneto and his Acolytes, Cassie shared a moment with Humberto (and also shared a short, but very passionate kiss with him) before he was taken in by Jean and Logan to Xavier's school. As she resumed her life as a citizen and superheroine, Cassie soon overheard of how happy Humberto was in Xavier's school, leaving Cassie glad to know that Humberto had a real family now.

Powers and Abilities

 * Genius-level intellect
 * Acrobatic skills
 * Hand-to-hand combat
 * Pym Particle Nanotech suit grants:
 * Ability to shrink to sub-microscopic size and enter the subatomic universes
 * Size-shifting from nearly microscopic to ~100 feet gigantic (both at extremes)
 * Ability to transfer her size-shifting ability to other beings and objects
 * Wall-crawling
 * Maintains strength of normal size in shrunken state
 * Superhuman leaping
 * Telepathic communication with ants
 * Superhuman strength, stamina, durability and mass in giant form
 * Quantum Key grants:
 * Access to Quantum Realm
 * Teleportation (via Star Tubes)

Weapons and Equipment

 * Pym Particle discs which allow Ant-Girl to will herself and other objects to reduce in size or enlarge
 * Pym Particle wrist device which allows Cassie to activate her Ant-Girl suit. It also allows her to design and resign the suit.
 * GPS Tracking Systems in her Pym Particle suit
 * Ant-Trackers which can be implanted on people and subjects Ant-Girl needs to investigate and follow.

Companions
Most evidently ants (which Cassie can control with her suit's EMP communication device) of four different species. Each species is useful for an unique occasion.
 * Bullet ants are useful to attack or stupefy enemies.
 * Carpenter ants are useful for air transportation.
 * Crazy ants can conduct electricity and are useful to carry cameras and other devices.
 * Fire ants are strong and durable, and are useful to create long structures, like rafts and bridges.