Process

The Process was a tyrannical leech-like monster that got caught up in an ontological paradox in which it hijacked the TARDIS and flew it on a direct collision course with The Time Scaphe, the culmination of months of hard time travel research by Rassilon and his Cult of Reason in an attempt to create a political revolution in which The Pythia would be booted off the throne and they would rise to power. The TARDIS was stretched and twisted into a big pretzel of paradoxes and anomalies, an entirely new dimension of nonsense and fantasy in which The Process could rule forever. However Ace put a stop to it and the TARDIS was put back to normal, The Process then vanished.