Alexandra Casoy (originally called Alexandra Heung), or Alex for short, is a spy/student and one of the main characters from Totally Spies!. She is the most active of the spies. She's an odd mixture between a tomboy and a girly-girl: she is the most athletic and fitness-minded spy of the team. She loves to play sports, especially soccer, and is always trying out some new fad diet. Along with Clover, she gets kidnapped to be the villain's girlfriend/wife a lot. Her signature color is yellow.
She was voiced by Katie Leigh in Seasons 1-2 and later Katie Griffin in Seasons 3-6. In the Japanese dub from the series, she was voiced by Omi Minami.
Alex has short black hair in a curly bob cut and light brown eyes. Her skin tone is tanned. She has black, Hispanic, and European ancestry and is proven to be 1/2 Hispanic in "Alex Gets Schooled", as her father is shown to be white and her mother appears to be Hispanic. Her father later appears with the same tan complexion as her in Season 6.
Alex has a taste for Chinese-themed outfits and her favorite food is Chinese food (wontons, apparently). Alex has the broadest variety of clothing out of the group. Usually she dresses trendy like Clover, or preppy and elegant like Sam, or a sportier type of outfit. She usually wears heels or flats, but often she wears sneakers. She's also shown to love to wear Giant Panda pajamas. She is the only one of the 3 whose bathing suits seen are all bikinis. In "The Getaway" and "Alex Gets Schooled", she is wearing a yellow bikini with a yellow pair of shorts. In "Eraser", she is wearing a green bikini with a skirt. She is wearing another yellow bikini in "Super Nerd Much" which is similar to the green bikini she wore in "Eraser". In "A Spy is Born I" it's revealed that Alex is the shortest member in the group, but in "Escape From WOOHP Island" she's taller than Sam, Clover, and Britney. In "Ho-ho-ho-no!" both she and Clover are taller than Sam.
In Season 1, her primary outfit was a light green shirt, pink skirt, and tan boots. In "Stuck in the Middle Ages with You" the color of her primary outfit becomes yellow and purple. In "Malled" her primary outfit becomes a lighter shades of green as her light green shirt changed to pale green, her skirt changed to sea green and her tan boots changed to blue green boots.
In Season 6's two-part finale "So Totally Versailles!" Alex wears her disguised form is a golden yellow and white long sleeved dress as her hair and face transformed into a classic styled look as her hair is extended to a French bun style.
Alex is an odd mixture between a tomboy and a girly girl: she is the most athletic and fitness-minded spy of the team. She loves to play sports, especially soccer, video games, and is always trying out some new fad diet.
Alex is also the most naive and absent-minded. She interprets some figures of speech literally.
Alex is also the youngest and most childish, seeing as her oldest and dearest friend is a stuffed turtle named Ollie and she has a teddy bear backpack. She is often seen as the little sister of the group, as Sam and Clover are the two big sisters who dominate over her. Another characteristic of Alex is that she's always about keeping her friends happy. She often serves as a link between Clover and Sam who have meaningless squabbles ("Abductions"). Alex is also a big animal lover and she likes petting zoos which is seen in "Mime World (Jazz Hands Return - Part 3)".
Despite being the most athletic, she tends to be clumsy, and has been prone to bad luck (Alex can be very superstitious). Alex is also the second girliest. She is very concerned about fashion and boys, to the same extremes as Clover; an obsession that Sam has trouble understanding.
Another one of Alex's hobbies is eating. Even though she may be the most healthy of the three spies, she likes to eat the most. In "Evil Valentine's Day", we see that she has a dream about candy. In the beginning part of the B-story in "The New Jerry" and the ending of "Animal World", we see her eating nonstop. During the 1st and 2nd seasons of Totally Spies, Alex was referred to (and shown) as a bad driver (Clover made a comment at one point in Season 5 indicating that it took more than three tries for Alex to get her driver's license), but in Season 3, Season 4, and Season 5, she was the one normally behind the wheel (indicating that her driving skills had improved).
Totally Spies! The Movie
Sam, Alex and Clover starting their new lives in Beverly Hills, California. As each of them were about to cross paths outside a sushi restaurant, nearby of WOOHP agents (including Jerry) purposely cause the giant sushi roll above the entrance to break off and chase after them, setting some nearby animals free in the process. The giant sushi roll, with the three girls log rolling on top of it, chases a baby pig to the street. The three girls are able to avoid it, save the life of the baby pig (which Alex later adopts and names "Oinky") and destroy the sushi roll before it causes any damage. After that, Alex, Sam and Clover introduce themselves and this starts their friendship when they later see each other again at their new school, meet the current principal Miss Skrich and their rivals, Mandy and Dominique and Caitlin.
Clover offers her new friends a change of clothes after Mandy sprays them with a chai machine, but they find themselves sucked in through a locker and into one of the offices of WOOHP. Here, they meet Jerry and fellow WOOHP agent Tad. Jerry reveals that WOOHP had been observing the three of them secretly since childhood, showing videos of each girl, and picking them as prime recruits for the organization. However, the girls are quick to reject the invite and refuse to join. However, they later are "forced" into training after each having traumatic experiences that seemingly relate to WOOHP. They agree to go through training and in 48 hours, complete the training.
After training, they are thrown into their first mission when famous celebrities, like rockstar Rob Hearthrob and animal psychologist Peppy Wolfman, have been mysteriously abducted. This also shows how the girls obtained their differently colored uniforms (thanks to a design suggestion by Clover). They first go to Wolfman's building where Alex has Oinky "go hog wild for mommy" as a distraction, and Oinky deliberately runs around the lobby with the other animals and the receptionist in pursuit. They later find that each went through a make over by a mysterious machine called the "Fabulizor", discovered thanks to security footage in Wolfman's office. They later see that everyone at school also had gone through the Fabulizor, having the same look the next day, and Oinky ends up going through the Fabulizor, getting the same make over as well. This is after nearly being blasted by one of Fabu's minions in a fighter jet while being flown back to school and after nearly avoiding Miss Skritch as they sneak back into school. Tailing Mandy that night, they find that all of those who went through the Fabulizor became hypnotized by a special chip in their cheek bones prior to the make over and Alex spots Oinky in the crowd and grabs onto him, with Sam and Clover grabbing onto Alex as they were abducted into a strange space station out in space. They then meet the mastermind behind the entire affair, Fabu, a runway model who quickly lost fame in five minutes on the runway and was ashamed of not being a part of the crowd during his childhood. The spies accidentally expose themselves and are captured by Fabu's strongest henchmen. He then relates his entire plan, to abduct everryone who went through the Fabulizor and place them inside a special space station which he calls Fabutopia to live out new lives in the posh surroundings, then use a missile to destroy all of Earth, before using his Fabulizor in reverse and give the girls each horrible make overs (Sam gets green skin, Clover grows a unibrow and Alex gets massive pimples). He then sets them to be blasted back to Earth in rockets. But just as he leaves, things get more difficult when Tad meets the girls again while they are still imprisoned and says he will let them fail the mission and stop Fabu himself, taking all the credit and regaining his "favorite agent" status with Jerry.
But after a fight with Fabu, Tad is strapped to the missile bound for Earth. The girls manage to escape and, after fixing the Fabulizor's damage to themselves, go after Fabu. They are unable to stop the missile from taking off but hitch a ride as it is rocketing towards Earth with Tad still attached to it. They are able to turn the missile around to destroy the station, surprising the girls since they had no idea of how to stop it earlier and Alex whacks at the control panel with the WOOHP manual. They then are picked up by a surprise appearance from Jerry in one of WOOHP's ships and rescue the kidnapped people from aboard the station (freeing them of the hypnotic trance by destroying Fabu's signal beacon in his staff) and evacuate safely, including Oinky, who Alex thought was never going to make it out in time, only to see him run fast to her, finally reunited with Alex before the missile explodes and destroys the station in a firework finale. They then chase after Fabu's ship, manage to destroy it and catch Fabu and his Sphynx in his escape pod. After the mission, the girls admit that the mission was difficult at first, but it also made them friends, so they accept their position as spies. Alex is invited for a session with Wolfman and Clover is offered a date by Rob Hearthrob over the phone. But before that, they later return to school to face punishment from the principal for the "damage" they caused when trying to avoid her earlier on in the movie (thanks to Sam using a laser lip stick to cut an escape hole in the wall earlier). But fortunately, it seems that thanks to WOOHP, they have a new principal, whose name is not revealed, and seemingly does not know about the girls' punishment and gives Sam high praise.
Sam, Clover, Alex celebrate getting even with Mandy for the last time, courtesy of one of WOOHP's gadgets, they are sucked away to another mission. The girls are quick to bring up personal appointments, but soon find themselves running from a WOOHP jet as it prepares to suck them aboard. But the girls are ready for their mission as they change into their spy uniforms and exclaim their friendship as the movie ends.
- Her First Voice Actress, Katie Leigh is best known for voicing as Fizzy from My Little Pony and Athena from Rainbow Butterfly Unicorn Kitty.
- Her Second Voice Actress, Katie Griffin is best known for voicing as Sam Sparks from Cloudy with a Chance of Meatballs (TV Series), Ruby from Max & Ruby Season 1, Sailor Mars from Sailor Moon, Laugh-a-Lot Bear from Care Bears: Journey to Joke-a-lot.
- She is Latina.
- In the 1990s pilot episode, she was Korean-American instead of Latina.