"We don't have all the time in the world after all, don't you see? If we don't fix this paradox ourselves - and soon - we'll run into more of those things like that one that erased Johnson. Worse yet, they might show up in your childhood, long before you learned about time travel or how to defend yourself."
While there's apparently a D&D Construct called Clock Roaches, that's not what this entry is about. Within the context of Time Travel Tropes, Clock Roaches are creatures or forces that clean up time, setting things back on the normal path and removing paradox. The term Clock Roaches implies they are non-sentient. Intelligent agents who fix time are usually known as Time Police. A great many settings use something of the likes as a way of fixing problems characters make, or as a threat from which characters must try to escape.
A very short list of Clock Roach examples (more are provided at TV Tropes)
- The Langoliers by Stephen King prominently features a form of Clock Roach.
- The episode Father's Day of the new Doctor Who has Clock Roaches.
- The Hounds of Tindalos are a sort of Clock Roach. They are part of the Cthulhu Mythos, though, so they aren't nearly so innocent or benign as most Clock Roaches. Rather than fixing time, they just feast on time travelers.
- In the RPG Continuum, The Inheritors could be seen as a form of Time Police or Clock Roaches, but that's pretty incidental to the other implications of their existence. The real Clock Roach in Continuum is force/effect called Frag.
Game and Story Use
- Clock Roaches could be entirely benign, a helpful bio-tech critter that PCs keep as pets, or carry around with them to fix annoying paradoxes.
- Clock Roaches could be horrible monsters that pursue time travelers across the dimensions
- A time traveler's HQ might include a room that is somehow warded against Clock Roaches, or a machine that hides the lair from their notice. Players in a tight spot can seek refuge there. However, if they do this too often, the Clock Roaches might start waiting just outside the place, complicating the PCs existence significantly.
- A sympathetic NPC might come to the PCs looking for help because of the Clock Roaches that are after him. It's not till much later that the PCs realize the beasts pursue him because of some horrible paradox he created that nearly destroyed reality.