Katherine "Kitty" Ko is one of the heroines in the show, and one major characteristic about her is her crush on Eric.
She wears a short sleeved white shirt, along with a green and yellow striped tie, a red and green plaid skirt and two red hairclips in her hair. In addition, she also wears a pair of knee high socks and a pair of dark black shoes. She had two left feet.
According to Todd Kauffman, Kitty is Chinese.
The age of Kitty is unknown. Some fans say that Kitty is 11. However, according to Todd Kauffman, she is 13.
In For Real Estate, Kitty's eye color is blue.
Kitty is a boy-crazy heroine despite being a little off-the wall, serves up totally stellar advice. She likes kittens. She is a fan of Joshua Sideburns, as seen in Comic Book Zombies. She does anything to get Joshua as seen in Teenage Mummies in Love, though Joshua seems not interested in Kitty's actions towards him. She also seems to have an interest in computers and anything with robotics as seen in Eric and the Maxum Brain Factory.
- In Like Supervillain, Like Son and Shopping Spree, Kitty can grow muscles that she don't like lift or push heavy objects to think about how very strong she was in the first season.
Kitty has a huge, obsessive and an overly attracted crush on Eric. Whenever she says something about her crush on Eric, Eric usually replies 'what?' then Kitty says 'what?' to cover up what she said to him, because she wants to keep her crush on Eric a secret.
Even though she and Vana are best friends, Kitty acts more of her lackey/assistant in the show.
According to YTV's website, both Kitty and Trevor hate each other very much. However, despite of that, in the series, they rarely show any signs of hating each other. Instead, they are shown as rather civil or even friendly to one another. But, there are some episodes that Kitty is shown to be annoyed by Trevor's stupity, while Trevor dislikes her for unspeakable reasons. Nonetheless, they are shown as good friends.
In the episode 'The Henchmen Challenge' is showed the only conflict between Kitty and Trevor. Kitty didn't like that Trevor was making Eric cheat and Trevor didn't like that she was trying to get Eric to play fair.
Because the Sidekick's greatest enemy is XOX, Kitty hates him the most. She'll do anything to beat the evil out of XOX, out of all the others.
Because Kitty also has a huge crush on Eric, she hates Mandy and even points a laser gun at her the first time she sees her. The animosity between her and Mandy is completely one-sided on Kitty's side and it is unknown wether Mandy will hate Kitty as much as Kitty hates her in season 2 or not.
- Kitty has worn a wedding dress twice in the show:
- Her first name comes from the Chinese, Japanese, Korean, and Vietnamese word (高 "Gāo" in China, Kō in Japanese, 고 "Ko" in Korea and "Cao" in Vietnamese) meaning high and tall referencing to her high personality and intelligence.
- Kitty is voiced by Denise Oliver, who also voiced:
- Like Eric, she was a orphan. This was proven in "Parent Teacher Night of Doom" that she built her robotic parents herself. It's unknown who she built her robotic parents that look like her real parents, it possible that when she was an infant, she remembers her parents' looks and voice.
- In Hello Dolly, she mentions that she has a little cousin who is 100 years older than Kitty. This could possibly mean that she may have been alone at her house with no family at all. This is also proven in To Party Perchance to Party when Kitty can be seen practicing her dancing skills alone in her house with no family member around.
- She is one of the three orphans of the show because of her being alone in her house after her real parents abandoned her (possibly when she was baby), got killed or both.