Dee Dee's Rival is the first part of the 35th episode in season 2 of Dexter's Laboratory, which first aired on April 15, 1998. In this episode, Dee Dee meets Lalavava, a classmate at her dance class, who tries to upstage her.
Dee Dee wakes up and gets ready for the first day of her dance class. She goes through a wake up montage similar to the one Dexter did in the episode Dexter's Rival. She gets dressed and Mom drives her to her dance class and her dance teacher Mrs. Babcock welcomes her back to the new year. Then, there is a noise heard and everyone directs their attention to a dark and scary figure in the shadows of the corner of the room. Mrs. Babcock says that this is their new student. She comes up and Mrs. Babcock says her name is Olga. Olga says that people can just address her as Lalavava.
Lalavava gets out on the dance floor and starts doing a dance that everyone seems to love. After Lalavava is done, she walks past Dee Dee and snaps her fingers in her face. Dee Dee wants to show that she is the real best dancer and she busts out and starts dancing. Lalavava gets mad at Dee Dee for trying to be better than her so she breaks out dancing and trying to be better than her. Dee Dee and Lalavava both start continuously dancing and trying to be better than the other. Finally, they both stop and are tired and exhausted from trying to beat each other. Mrs. Babckock is equally impressed by the both of them and she says that both of them will share the title of the main dancer in the play together. Dee Dee and Lalavava both shocked and unhappy with this run home and both say that they will get help from their brothers for this.
Dexter is working in his laboratory on an invention. Then, he hears Dee Dee coming and he sighs and takes out a hammer and he smashes his invention before Dee Dee gets there. Dee Dee says that she needs help with a problem she's having with another girl at her dance class. Lalavava comes home and goes to her brother Mandark. Lalavava says that she is having problems with another girl at dance class. Dee Dee begs and pleads for Dexter to help her. She acts so nice toward him complimenting him and treating him good so that he will help her. Lalavava is rude and mean to Mandark. She also threatens to break his face, wrangle his neck, and beat him up if he doesn't help her. Mandark trembles in fear before Olga and Dexter decided that he would pity help Dee Dee with her problem. Dee Dee thanks Dexter by giving him a kiss and Lalavava "thanks" Mandark by punching his nose and laughing.
Later at the ballet dance, the play is about to begin and Dexter, Mom, and Dad are sitting in the audience watching. When they play begins it starts off calm and peaceful with one little girl dancing, then when Dee Dee and Lalavava come up, they are in giant robot suits. This shocks the audience because of what they see. Dee Dee and Lalavava both start dancing in there which rumbles everything and breaks stuff apart. Dee Dee and Lalavava competitively dance and then, their dance breaks out into a fight. They both start punching and blasting missiles and firing lasers at each other trying to destroy each other, soon they both beat each other up and the person in the play everyone loved the most was the little girl at the beginning of it. Everyone cheers and throws flowers at her and Dee Dee and Lalavava are up there thinking about how they shouldn't be fighting. They both find out that they both have nerdy brothers with secret laboratories and they decide to put their differences aside and become friends and so they both break through the wall and walk off to the mall.