After he turns down his dad's invitation to go fishing, Billy gets a tiny, weakling, pet fish(Arnold Schwarzenegger), which he names Little Porkchop. Then, to make Billy happier, Grim makes the fish grow overnight to become a giant. However, Billy takes Porkchop to play under the Sun, and never gives him water again, so he burns to ashes and is flushed down the toilet. In the end, Billy's dad returns form his fishing trip having caught Porkchop, which returned to his normal size, but plans to cook him.