Ariel adopts a baby whale, much to the dismay of her father, King Triton.
The Little Mermaid
Season 1 Episode 14: Eel-Ectric City
Pearl, a mermaid who is obsessed with partying, takes Ariel and her sixth eldest sister, Alana, to Eel-Ectric City instead of to her house, while Sebastian and Flounder follow.