"That Darn Katz!" is the eighth episode of the sixth season of the animated comedy show, Futurama. It first aired on Comedy Central on August 5, 2010. In the episode, Amy's rejected doctoral dissertation—a device to harness the Earth's rotational energy—is used by evil invading space cats to fix their own slowing planet. Since the invention will cause the Earth to stop turning, Amy and Nibbler must team up to stop them while their co-workers have fallen under the thrall of the cats' cuteness. The episode was written by Josh Weinstein and directed by Frank Marino. This was the first episode since "Rebirth" to use the full intro sequence, and as a result, includes a classic cartoon before the opening credits. "That Darn Katz!" was generally well received by critics, who enjoyed another unexpected pairing, this time between Amy and Nibbler, and the character development for both that arose from it. Plot Amy prepares to defend her doctoral dissertation in Applied Physics: a machine capable of harnessing the Earth's rotation and magnetic field to produce energy. Nibbler confronts Leela, displeased with her treatment of him as a pet and desiring to be treated as a crewmember. At Amy's defense her proposal is rejected, mostly due to Professor Katz' pet cat, who distracts her and stimulates her allergy to cats. The crew return to Planet Express, unknowingly accompanied by the cat. The crew—with the exception of Amy, who remains resentful, and Nibbler, who is jealous of Leela's affection for the cat—finds the cat endearing. Amy and Nibbler become suspicious, rationalizing that no creature could behave so cute without an ulterior motive. They discover that Professor Katz was a puppet controlled by his cat, Katz, the entire time, who is part of an alien race of talking cats that invaded Earth during 3500 BC in ancient Egypt. The space cats' home planet, Thuban 9, began losing its rotation, and they discovered that Earth had the correct orientation and magnetic field to harness its rotational energy. They built the Great Pyramid of Giza—an energy transfer antenna—and planned to send Earth's energy to Thuban 9, but became distracted by their worship by the Egyptians, forgetting their technology over the centuries. Amy's thesis provided the cats with their lost technology, allowing them to begin again. Katz and his colleagues place the crew under their influence with "hyper-cuteness", forcing them to build Amy's invention. Imprisoned by