Heathcliff catches a mercat (half cat-half fish) whose singing bewitches him. He takes her home and keeps her in a tank in his room. Meanwhile the lighthouse keeper who saw Heathcliff catch the mercat is bewitched by the mercat's mermaid owner, who orders him to bring the mercat back to the sea.; Heathcliff trashes cars so Iggy will have plenty of business for his car-washing service.; Billionaire Mr. Gotbucks wants to tear down the Elite Fish Market, Heathcliff's favorite store. Gotbucks hates fish because he was humiliated in a fishing tournament by catching the smallest fish. Heathcliff helps him catch a huge fish to win a tournament and in return Gotbucks allows the Elite Fish Market to reopen.; Heathcliff takes photographs of the city dog catcher being friendly with dogs and gives them to the chief of the city pound.