Star whale
A Star Whale was a giant space-borne creature.
Biology
The Star Whales were giant alien creatures, resembling Earth's whales in basic structure. They had several flippers and tentacle like protrusions down their stomach, as well as smaller spiked tendrils on their back. Star Whales were capable of travelling through space, at speeds comparable to a spaceship. Though they could communicate in an atmosphere, their sounds were too high pitched for Humans to hear. They were capable of bioluminescence, with glowing patterns around their tendrils. (DW: The Beast Below)
History
An ancient and benevolent species, the Star Whales had, according to legend, guided early space travellers through dangers on their journeys through space. By the time of the 29th century, the species was believed to be all but extinct save for one, who was theorized to be the last of its kind. When Earth was facing destruction because of solar flares, that Star Whale was drawn to Earth. All the peoples of Earth had managed to escape in massive city ships, but the people of the United Kingdom lacked the supplies to create an engine. The Star Whale intended to offer its services to the stranded people.
Unfortunately, the people of the UK misinterpreted this gesture of good-will and captured the whale, building their ship right on its back and carving an opening to its brain to torture it into moving. The city built on its back became known as Starship UK. While the government realized the moral problem, they believed that the Starship UK would be destroyed if the Star Whale was freed, killing the population. To deal with this, they allowed citizens to vote on the matter, either choosing to "Forget" (and have their memories erased) or "Protest" (at which point they would be fed to the Star Whale).
When the Doctor and Amy came to the Starship UK circa the 33rd century, the Doctor began to investigate the ship. Eventually the Doctor discovered the heart of the ship, where Hawthorne and his workers were torturing the Star Whale with electric shocks to keep it moving, and faced the impossible situation. Seeing no other reasonable options, the Doctor was prepared to lobotomize the Space Whale so it would no longer feel pain from the torture. Amy, however, noticed the Whale's neural tendrils affectionately playing with the children. She quickly put the pieces together and ran over to the control system to press the "Abdicate" button, freeing the Whale. The ship, however, did not explode as was originally feared but instead started to move faster, as the Star Whale had come willingly and was still willing to help the people of the UK. (DW: The Beast Below)
Bears some resemblance to the Cash cow. TW: Meat
