Trixie Lulamoon is a female unicorn magician who is the former main antagonist of Ed, Edd n Eddy XL as well as being a supporting protagonist throughout the rest of the series. Like Kevin, she is voiced by Kathleen Barr.
During the events of the first six seasons of the show, Trixie was described as a boastful, power-hungry and arrogant unicorn sorceress who would use magical and underhanded tricks with the help of her devious, rather incompetent minions, Kevin and Eddd, to try to dispose of the Eds, so she could claim the Fourth Kingdom for herself and that all she wanted was more power. It is revealed that she is the granddaughter of Princess Luna, which the Eds found out in the final level of Ed, Edd n Eddy XL: The Ed-ventures, which was titled Eds of the Night. Trixie would often mistreat her minions whenever something doesn't go as planned for her.
In Ed, Edd n Eddy XL: The Aperture War, Trixie is first built up to be the main antagonist. She is seen at the Rocky Plains as she challenges the Eds into a magic duel, but is eventually defeated and as the Eds take off on their adventure, she sadly whispers, "I'm sorry...". She is then seen rescuing the Eds before Twilight Sparkle could kill them. After the Foullanders and Breakfast People became friends again and Twilight has been redeemed, Trixie explained to the Eds that the reason why she was their archenemy from the very start of the series as a power-hungry and disrespectful snob was because Twilight Sparkle constantly doubted her all the time and would make her a laughing stock. She had to work on a rock farm for a living and she had to get away with being malicious and heartless, so she could extract her revenge on Twilight for having everyone and everypony laugh at her. She regrets everything she had done to everything and everyone/everypony and asks the Eds for her forgiveness.
The Eds accept her apology and Trixie becomes their friend throughout the rest of the series' run, making her generous, kind, friendly, honest and loyal. She also changes her name to "The Great and Apologetic Trixie".
"The Great and Powerful Trixie...!"
"Now let's see what your little charm can do!"
"I made it all up, Eds; the reason why I was your enemy was because Twilight doubted me and made me a laughing stock my whole life! She's the one who caused me to become the dictator the three of you knew me as and that she's the one who started this horrible war. But now she's sworn not to start another one after Double D's kind words. I've treated you and your friends so horribly, I didn't know what came over me. Kevin and Triple D aren't actually my goons, either. I hope you can forgive me..."
"Don't you think the Great and Apologetic Trixie is the most forgiving unicorn in all of the Fourth Kingdom?"