What is the name of the giant space creature in 'The Beast Below'?

The giant space creature in “The Beast Below” is a Star Whale. The 2010 Doctor Who episode reveals that Starship UK is travelling through space on the back of this enormous, intelligent creature, which carries the surviving population of the United Kingdom.

The Star Whale arrived near Earth after solar flares made the planet uninhabitable. Rather than abandoning the ship’s passengers, it willingly carried them to safety. The ship’s government secretly tortured the creature with electrical impulses, believing that its pain was necessary to keep it moving. The Doctor initially considers making the Star Whale brain-dead to end its suffering while preserving its guidance.

Amy Pond discovers that the creature is not being forced to help. When Liz 10 chooses to abdicate, the Star Whale continues travelling and accelerates, suggesting that it came to Earth voluntarily to rescue humanity’s children. The Dalek and Great Intelligence are unrelated Doctor Who threats, while the TARDIS is the Doctor’s time machine rather than a living space creature.