Yolanda Perraudin, originally known as Dorothy Perraudin, is the nurse at Kadic Academy.
She is tall, short-haired blonde, who wears a short blue skirt, a crimson pink shirt, brown heels, blue earings, and a lab coat.
Yolanda is the only known worker at the Infirmary, and probably runs it.
She was first seen treating Jeremie in X.A.N.A. Awakens, Part 1, after he got electrocuted by the vending machine (which was controlled by X.A.N.A.). In X.A.N.A. Awakens, Part 2, she treated Sisi after she got electrocuted by the electrical orb.
In Killer Music, she ordered the principal to call the ambulance to pick up paralyzed Odd. Later when Yumi brought paralyzed Sisi to the Infirmary, she was put into coma by X.A.N.A.'s killer music.
In Code: Earth, she treated injured Jeremie when he fell from the stairs and told him that he cannot walk for at least one week.
In X.A.N.A.'s Kiss, a Polymorphic specter took an appearance of Yolanda to kiss Jim. Later in the episode, when Jim confessed his feelings to her she was embarrassed and told him that she's already engaged without believing him that she kissed him.
In Tip-Top Shape, she had organized the medical checkup for every student at Kadic and later was possessed by X.A.N.A. to bring Aelita to Lyoko. She also fought in the Factory with Odd after he was amplified by Jeremie and the tower he activated.
In Tidal Wave, she tutored the students about healthy lifestyle and balanced diet during the Nutrition Day.
In Aelita, she told Odd that he's suffering from severe plantar perspiration and gave him a cream that could kill the smell but the cream turned out to be smelling even worse than his feet.
In Replika, she helped Jim to get to the Infirmary after he had an accident during PE class and rebuked him for straining his body. This was her last appearance in the series.
- The Chips Are Down
- Attack of the Zombies (appeared as a zombie)
- X.A.N.A.'s Kiss
- Tip-Top Shape
- She was the only one who could generate huge yellow-colored energy orbs from her hands when possessed by X.A.N.A., which were similar to Aelita's energy fields are in the real world.