Ariel is a mysterious teenager from Atlantis who occasionally appears through a doorway in reality. She is the princess from the "Isle of Dreams" who comes seeking more people for her home. She has chosen the Twist and Gribble kids to join her there in paradise forever. Ariel needs a husband so that she can replenish her kingdom's dwindling race and she wants Pete to be the man she marries.
The newest member of the Twist family Ariel Twist is named after her.