Heathcliff and the Catillac Cats

Heathcliff's Pet [Heathcliff] (1x19)

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Heathcliff hears Iggy saying how wonderful it is to have a pet, and decides he should have a pet too. He tries out Spike and Mungo, but they do not make good pets at all. He frees a live lobster from the fish store which makes a great pet until the lobster begs to go home to the ocean and Heathcliff generously complies.