Letta is a recurring alien villain in My Life as a Teenage Robot. She is the leader of the Space Bikers. She is the principal of their home planet's elementary school. She holds a personal grudge against Jenny for destroying her bike.
Letta and her gang are from a planet that is inhabited by peaceful fishlike aliens. Her identity as a Space Biker had been a secret (until Jenny and Tuck exposed Letta and her cohorts as dangerous villains in Voyage to the Planet of the Bikers). Letta was the principal of an elementary school on her home planet. But she and her gang sneak away and don their biker personas to blow off steam on the weekends and wreak havoc for fun, usually by crashing parties on other planets, such as Earth.
She holds a grudge against Jenny, and often returns to Earth with the Space Bikers to torment her and her friends.