Disney's The Little Mermaid
Whale of a Tale
S1 E1:
Ariel finds a lost baby killer whale - Spot. During migrating season, he was separated from his mother. Like most children who find stray pets, she takes him home with her. All is well until Spot outgrows his new home. Triton soon discovers Ariel's secret and demands Spot to be turned loose. Except there's one small, or in Spot's case, one VERY LARGE problem. He's no longer able to survive the wild sea-life.