Like her show counterpart, Téa seems to be very into the ideals of friendship, though doesn't blab about them as often (when she does, though, it seems to annoy everyone, especially Yami). She is a lot crueler than on the regular Yu-Gi-Oh! anime, criticizing Joey for having no chance of winning Duelist Kingdom as he is a comic relief character in Episode 5 (though she seems to dislike Bakura and Tristan more, wanting to ditch them in episode 18 and then telling Joey they can't let Tristan breed in Episode 22).
She is obviously in love with Yugi (Yami), and in many occasions have acted very jealous when other people "flirt" with him. However in the Abridged Movie Trailer, she admitted she was only using Yugi to get to Yami Yugi, but in the film she blatantly comes onto Yugi on multiple occasions, and seems to be genuine about it and in episode 46 she gets annoyed that Yugi (regular) is not making out with her and when Yugi asks if Téa heard something, she asserts "The only thing I can hear is the sound of you not making out with me!". She officially admits to loving Yami in Episode 21, and since then, Yugi has been much less friendly to her, calling Téa "Jezebel" in Episode 21 and "slut" in Episode 22, where she also was fawning over Duke Devlin for most of the episode. She fawned over Marik in a similar fashion in Episodes 34 and 39, saying Marik would fit "perfectly between my thighs...I mean within our circle of friends". In that episode she also gave Duke Devlin a spanking which seems to imply her character is getting kinkier as the show is going on.
She's also a kleptomaniac, having attempted to steal her friends' wallets on two separate occasions, including the marker used in Episode 1 (and also wanted to snoop through Pegasus' room in Episode 19). Among others, she has a Happy Feet penguin, a Sailor Moon, Bubbles, and Jigglypuff cards in her deck. She has compared the plot line (Episodes 9, 19 and the Abridged Movie) to bad fanfics. Despite her hatred for all Yu-Gi-Oh related fanfics, it's revealed that in Episode 23 she writes Harry Potter fanfics and is a Harry/Hedwig-shipper.
She despises Mai Valentine, likely due to her liking Yugi, despite the fact that Téa likes Yami. Among others, she has referred to Mai as "Mai Skankentine", and "Skankity Slut Slut". When Mai tried flirting with Yugi in one episode, Téa responded by saying "Back off bitch, he's mine" in a deep, demonic voice.
Due to the fact LittleKuriboh is male, Téa's voice sounds high-pitched and slightly strangled; however this also creates a humorous effect.
Her friendship speeches apparently have started to have a brainwashing effect on people unfortunate enough to get caught in one, as shown in Episode 25 when she got Johnny Steps caught in one for a couple of hours, he left saying "must... go... get... friends" in a monotonic voice. She also boasts that "friendship is the most powerful force in the world! It's even stronger than Chuck Norris!", to which Joey responded, "Blasphemy!". She seems to enjoy the effects of her speeches and cannot resist the urge to speak one. Téa also admits to being a total spaz which allows her to be really good at DDR (though her life goal is to become a table dancer in New York, something she may have done after the events of the Abridged Movie). In the second episode of Cr@psule Monsters, she nicknames her monster "Friendly McFrienderson III."
In the Abridged Movie, Téa is regarded with contempt; when she attempts to jump into the Pyramid of Light to be with Yugi, Pegasus tells Mokuba and Solomon to "just let her jump". When she appears in front of Yugi, Joey and Tristan, they sarcastically remark "Oh, good," and in a similar fashion, "Oh, no" when she falls. Anubis even describes her as the most annoying character in Yu-Gi-Oh and plans to kill her to do the fans a favor. (
unfortunately, he fails.)
In Cr@psule Monsters, Téa is the only character who seems to remember everything about the past events in the main series, whereas everyone else has forgotten about every other character, the Duelist Kingdom tournament and even Duel Monsters itself (except for Yugi, who remembers everything but the card game). Tristan claims that she's living too much in the past in the beginning of the second Cr@psule episode and seems to have finally stopped referencing the card game. She and Tristan both believed in the candy Alex Brisbane mentioned and somehow acquired monsters used to fight other creatures. ("Friendly's" power seems mainly to just be healing people with friendship/magical powers).
In Episode 49, the first time the series strayed from the original plot, her body is possessed by Crump. To prove this, at the end of the episode, her face fades from high-pitched, but then tries to reach it as Crumps is in control. As well, after she asks Yugi a question, it closes in on her left eye dramatically, and shows Crump laughing evilly before shouting "PENGUINS!"
While being possessed by Crump, Téa becomes extremely lecherous and makes several blatant attempts at having sex with Yugi ("Dammit Yugi! TOUCH MY BOOBS!"). She also shares Crump's fetish for penguins, but at a more subtle level. She was returned to normal later when Crump was kicked out of her head by the lingering soul of Marik, who was possessing her before Crump. When the group returned to the real world, it is implied that remnants of Crump's influence remained in Téa's mind, seen when Tristan asked Téa if she felt different after being possessed by Crump. She responded with "there's nothing wrong with my penguins," followed by "there's nothing penguins with my brain," then finally "there's nothing penguins with my penguins."