Ravager (Sphere of Freedom)

The Ravagers were a name given to a species of creatures numbering in the billions that had an insatiable hunger to devour everything in the universe. When grouped together in one place, they resembled a neutron star. (AUDIO: Sphere of Freedom)

Biology
Ravagers were mostly brown-grey humanoid creatures with few defining facial features except for their large mouths and lack of eyes. They were not able to speak human languages and usually made indeterminate noises unless translated by a TARDIS, which made one individual sound like a young girl.

They were a threat to the stability of the universe unless held back due to their ability to eat anything and spread easily throughout the universe. The one thing that stopped them from devouring matter was the feeling of their own fear, which they termed "the sweetness". If released in their full force, however, they could destabilise the structure of space-time within minutes. (AUDIO: Food Fight)

History
The threat of the Ravagers was first discovered by the people of Tarlishia who worked to prevent their escape for decades. Audrey Mohinson believed that a salvaged Gallifreyan control node could send them back in time, devolving them in the process, but it failed to work as the Ravagers simply absorbed the temporal energy, putting the future of the planet under threat. (AUDIO: Cataclysm)

Audrey spent at least the next twenty years trying to stop them, eventually founding the Sphere of Freedom. Although seemingly just a planet creating immersive reality games, she designed the most expensive and popular one, Fugitives, specifically to hold the Ravagers back. Using time eddies created by the node, people would be displaced in time and the resulting space-time shadows would feed their fear back to Ravagers. However, it was not until the Ninth Doctor met them that he realised they were addicted to their own fear, so he worked with Audrey to feed their fear from the game back to them, stopping them permanently. (AUDIO: Food Fight)