Lucinda, the professional mermaid, appeared in the Where's Waldo? episode "Draining the Deep". After ruining the "Undersea Dance and Yodeling Contest", the deep-sea divers gave her one last chance to prove herself useful. She was placed in charge of guarding the great sea plug. But when Lucinda took a short lunch break, a ship of pirates (led by Pegbeard) stole the plug. Lucinda became the pariah of the sea.
When Waldo comes to the Land of the Deep Sea Divers, he helps Lucinda find the plug and restore the draining sea.