The Beast
The Beast was a Demon that was imprisoned in the centre of Krop Tor. He claimed his existence was from before the Doctor’s universe was created and identified himself as Satan.
Biology
His physical body resembled a massive humanoid with red skin, two large ram-like horns and a corpse-like face. The Beast could manifest himself through electronic media. It’s mind could leave it’s body and possess a single hive mind collectively, like the Ood, or a single human mind individually. It had the power of telepathy and when possessing a host, it had telekinesis.
When The Beast possessed a human subject, the victim’s skin would have strange markings all over their face and body and were able to speak in different pitches simultaneously. The eyes of those possessed by the beast glowed a fiery red. The Beast could also project fire from his mouth as could it’s possessed hosts. The hosts could also physically survive in a vacuum indefinitely.
Appearances
The Impossible Planet/The Satan Pit (TV)
Jetsam (Comic)
The Beast is Back in Town (Comic)
To Heck and Back (Comic)