The Undersea Kingdom

 is the seventeenth episode of the second season of Star Teens Unite!.

Summary
Nemo invites the Star Teens to an underwater suburban area to see her mother and sister, but things go awry when a gigantic octopus attacks the suburbs.

Debuts

 * Coral (Nemo's mother)
 * Maris (Nemo's older sister)

Characters

 * Ella
 * Inidra
 * Sandra
 * Felicia
 * Lisa
 * Tanya
 * Sheila
 * Veronica
 * Trixie (Ella's mother)
 * Julie (Ella's younger sister)
 * Nemo
 * Coral (Nemo's mother)
 * Maris (Nemo's older sister)
 * Gigantic octopus

Voice Cast

 * Aimee Carrero - Tanya
 * Ariel Winter - Julie, Nemo
 * Colleen O'Shaughnessey - Trixie
 * Grey Delisle Griffin - Sandra
 * Jennifer Hale - Veronica
 * Jessie Flower - Maris
 * Jodi Benson - Coral
 * Kari Wahlgren - Ella
 * Kate Micucci - Inidra
 * Kimberly Brooks - Sheila
 * Tara Strong - Felicia
 * Vyvan Pham - Lisa

Trivia

 * Nemo's mother Coral and sister Maris debut here.
 * Coral's actor Jodi Benson also voices Ariel in "The Little Mermaid" and Aquagirl in an episode of "Batman Beyond".