Oroborus

The Oroborus was a snake-like creature able to traverse dimensions and feed on time. It was also known as "the cosmic serpent". It could consume chunks of the timeline; the more it ate, the more it grew. It could shed its skin like real snakes. Once it was fully grown it could consume an Earth-sized planet in hours.

Some time before 2050, the Oroborus turned Centauri into a black hole by siphoning off its future. This event was known to Alistair Gryffen.

The Oroborus made its way to Earth through Gryffen's Space-Time Manipulator and hid in Gryffen Manor's basement. It consumed time until Starkey discovered what was going on and lured it into the Manipulator's path, sending it away. (TV: Oroborus)

Behind the scenes
Its name comes from Ouroboros, the symbol of the circle of life depicted as a snake eating its own tail.