Terry Pratchett's most infamous groups of supernatural monsters, the Auditors and Things, decide to duke it out against each other, since they're getting in the way of each other in trying to warp the Universe. A Discworld god could turn you into a pillar of salt and a Hell demon can viciously torture you for aeons, but even their darkest actions have a vitality to them that the genuinely alien Auditors and Things lack.
The Auditors see life in general as a messy glitch in the Universe that has to be debugged, while the Things out in the void between realities see the whole Universe as a warm inviting light to envelope their twisted forms over. In The Thief of Time the History Monks, a ancient institution, deem the Auditors just as bad and in some way worse than the Things, due to their less overtly dangerous appearance (a grey robed figure is less conspicuous than some squid headed bat creature riding a particularily angry bicyle).
The Auditors can assume physical form by their own volition (they turned into wolves in Hogfather and humans in The Thief of Time) but that can easily backfire on them due to the Auditors taking on biological form too well. They can manipulate reality quite deftly in certain circumstances, as expected, but they're still hamstrung by the Rules (hence why they exploit loopholes in their attempt to "delete" life).
The Things that featured in The Colour of Magic and Moving Pictures could assume physical form through human belief, although that was not without its hazards. Other times the Things came through when concentrated magic that was akin to dividing by zero was used (as seen in The Light Fantastic and Sourcery).
The Auditors see life in general as a messy glitch in the Universe that has to be debugged, while the Things out in the void between realities see the whole Universe as a warm inviting light to envelope their twisted forms over. In The Thief of Time the History Monks, a ancient institution, deem the Auditors just as bad and in some way worse than the Things, due to their less overtly dangerous appearance (a grey robed figure is less conspicuous than some squid headed bat creature riding a particularily angry bicyle).
The Auditors can assume physical form by their own volition (they turned into wolves in Hogfather and humans in The Thief of Time) but that can easily backfire on them due to the Auditors taking on biological form too well. They can manipulate reality quite deftly in certain circumstances, as expected, but they're still hamstrung by the Rules (hence why they exploit loopholes in their attempt to "delete" life).
The Things that featured in The Colour of Magic and Moving Pictures could assume physical form through human belief, although that was not without its hazards. Other times the Things came through when concentrated magic that was akin to dividing by zero was used (as seen in The Light Fantastic and Sourcery).