Wonder Girl

Wonder Girl (real name ) is a member of the Team.

Personality
Wonder Girl is a very tough young girl, with a very energetic, carefree and eager personality. In general, she prefers taking on foes stronger than herself. She loves to fight, and enjoys missions in which there will be physical confrontations. Sitting on the sidelines is less to her liking.

She can occasionally lose focus when impressed by something, but can regain focus when corrected. Her teammates have also remarked that stealth is not her strong suit.

Physical appearance
Wonder Girl has a slender yet muscular build with blue eyes and blonde hair with unkempt bangs. Her hair is long, running down her back, and she wears a black headband. She wears a black sleeveless top with two stylized golden W's on it, which resemble the W's that Wonder Woman wears across her camisole. She has red pants with two white stripes on the sides, and blue shoes. When her Stealth-tech is active, her entire costume, shoes and all, turns black, with the exception of the stylized W's, which turn gray.

Like Wonder Woman, she wears two silver bracelets and star earrings (though silver instead of red), and uses a golden lasso that hangs at her waist.

2011-2015
With her mother's consent, Wonder Girl became the protégé of Wonder Woman and joined the Team.

2015
Wonder Girl was in the mission room waiting for the briefing when Zatanna and Rocket arrived. She was surprised when Zatanna kissed Nightwing a happy birthday in front of everyone.

When the two fresh Leaguers had left, Nightwing started the briefing. He and Cassie would be Alpha Team.

On the way to their target, Wonder Girl explained she was excited about being on Alpha Team with him. Nightwing empathized, and told him of his early days on the Team. He also explained why he chose Cassie to come with: they were recruiting a new member, and as she was still new to the Team, she could be vital.

On the roof of the Rio Grande High School, Nightwing quickly went through their data on Blue Beetle with her, before sending her to meet Jaime Reyes, the Blue Beetle. Nightwing figured that sending a girl would reduce the chance of the meeting ending in a fight.

Cassie moved in and surprised Jaime, even more so because she explained she wanted to talk about Blue Beetle. Nightwing then joined the conversation, and offered their friendship.

Their conversation with Jaime was cut short when the Watchtower contacted Nightwing. While he conferenced with the Watchtower and the Cave, Wonder Girl kept Jaime from interfering.

Nightwing and Wonder Girl discussed what to do next. Cassie was especially upset that she wasn't abducted along with Wonder Woman, as Superboy did disappear. Jaime wanted to excuse himself, but Nightwing insisted that he'd consider. He told him that Ted Kord was a friend of his, and he would've wanted him to join.

Cassie tried convincing Jaime by telling him how the Team had helped develop her skills and powers, but Jaime was still hesitant. He wanted to discuss it with Peacemaker, Green Lantern and Captain Atom, but all were unavailable. Their conversation was cut short by another emergency, this time in Metropolis. Nightwing asked Jaime if he would like to come along.

Alpha Squad took the Super-Cycle to Taos, with Blue Beetle in tow.

2016
When Lobo was trying to kill secretary general Tseng, Wonder Girl and Batgirl were called in, and distracted the alien. Batgirl tried to escape with Tseng, while Wonder Girl took care of Lobo. Lobo eventually prevailed and revealed that Tseng was a robot, operated by a Krolotean. Lobo left with the Krolotean, as Wonder Girl looked on.

After the Justice League identified locations around the world with Krolotean activity, Wonder Girl was assigned as Alpha Squad along with Nightwing, to capture the remaining Kroloteans in Philadelphia.

Wonder Girl and Nightwing took the Super-Cycle to Philadelphia. Their targets got away.

After the Gamma Squad (Robin, Blue Beetle and Lagoon Boy) saved the abductees from the Kroloteans, Wonder Girl arrived on the Super-Cycle.

Wonder Girl and her mentor, Wonder Woman, were part of Delta Squad during the mission to stop the Kroloteans on Malina Island. They were called in for backup when the enemies started to retreat. They both took out multiple Mechs. When they learned the base was set to explode, they picked up Aquaman and Lagoon Boy and retreated to the Bio-Ship.

As the Leaguers accused of crimes on Rimbor prepared to depart, Wonder Girl expressed her desire to come along. Wonder Woman refused, as only a select group would be necessary, and she could never convince her mother to allow it.

Aboard the Bio-Ship on her way to a mission to Bialya with Miss Martian, Bumblebee, and Batgirl, Wonder Girl was briefed by Nightwing, though she already knew what the mission details were. She laughed with the other girls after Batgirl called Nightwing out on why he had to justify choosing an all girl team.

Wonder Girl was upset when Miss Martian ordered her to stay behind as a lookout while the other three girls infiltrated the base. After protesting briefly, she accepted the instruction. Wonder Girl watched the three girls enter the base, before spotting a truck carrying Mammoth, Icicle Jr., Devastation, Shimmer, and Psimon, who was previously thought to be hospitalized. Realizing she couldn't contact her teammates without Psimon knowing they were there, she had to warn them by finding them in the base.

After finding Miss Martian, she set out to warn the others, but was discovered by Devastation, who pinned her down. She fought her and several Bialyan soldiers off, and made it to the rendezvous point. They were later joined by Bumblebee, who notified them of Batgirl's capture. They set out to liberate her, and the abductees she had found.

Wonder Girl stayed in reserve while the others rescued Batgirl. She forced open a gate where Batgirl could fly a plane with all the abductees through, and made sure Devastation couldn't get to her. Unfortunately, the plane was damaged, and without its wings, fell off the end cliff at the end of the runway. Wonder Girl tried to lift it up, but it was too heavy. However the Bio-Ship saved them both.

Cassie was disappointed their mission gave them so many unanswered questions, but Nightwing assured her that it was a success nonetheless. The other girls congratulated Wonder Girl on her successful mission with a group hug.

Cassie was one of the Team members, past and present, who had come to mourn after they had been told of the death of Artemis.

Cassie attended Raquel Ervin's bridal shower with all the other female members of the Justice League and the Team. After the party was interrupted by an armored car robbery by Captain Cold, Cassie assisted in his defeat.

Powers and abilities

 * Flight
 * Invulnerability
 * Expert hand-to-hand combatant: She has been trained by Wonder Woman herself; in combat, she has bested Devastation once.
 * Super strength
 * Superhuman reflexes

Equipment

 * Bracelets
 * Lasso
 * Stealth-Tech: By pressing the W's on her costume, she is able to activate her stealth tech.

Background in other media

 * This Wonder Girl is based on Cassie Sandsmark; Cassie is the third person to be called Wonder Girl. The first was Diana (the later Wonder Woman), the second Donna Troy, a founding member of the Teen Titans. Cassie is the daughter of Zeus and archeologist Helena Sandsmark, a friend of Diana's. She first became Wonder Girl clandestinely (and sporting a black wig), and was only later accepted by Wonder Woman. She joined Young Justice, and later became the leader of the Teen Titans.
 * This is Cassie's first animated appearance.
 * Wonder Girl was one of the few characters declared off-limits in the early production process, meaning that she could not be used during the first season. That restriction was eventually lifted.