The peripheral beast is often considered naught but a myth. The common defense is that if you can't look at a creature how does it exist? A dangerous assumption indeed. The peripheral beast is very real and very dangerous though almost none have seen it and even fewer have lived to tell the tale. The creatures live mostly on the plains though they occasionally will be in forests or jungles that border plains.
They are not exceptionally large, standing only around five and a half feet tall and they are of average human width. No full description exists of the beast but by all accounts they have been seen to be bipedal and have very large claws, around a foot, possessing a non-prehensil tail.
The fact that they are rarely seen isn't due to invisibility. No this creature has a strange ability indeed. You can't look straight at it. If a person tries to look directly at them they see empty space, but they can be seen in the peripheral vision. Hence the name peripheral beasts. Stranger still is that their corpses turn into ash instantaneously. So attempts to kill the for study have all but failed. All attempts at using magic to see beyond illusions or invisibility have also failed. They can also be seen in natural reflections(e.g. puddles of water) though use of mirrors has failed to locate them. They have the ability to move very quietly which combined with their visual hiding ability makes them very hard to locate. Though they do make sounds and the few warriors who have killed one say that heightened hearing and good peripherals are all that saved them.
All known deaths of a peripheral beast have been at the hand of a melee weapon as it's seemingly impossible to hit one with a missile and even magic misses.(Though some mages have claimed to have roasted them with fireballs, but that's hard to prove as they turn to ash upon death and the ash is difficult to differentiate.)
From what little data on the beasts that has been gathered it appears that they work in groups of four to eight. They also seem to possess some form of intelligence as they appear to communicate with each other. Communication is a mix of low hums and shrieks. Their motives for attacking people is not well known and it's assumed they are territorial.
Corpses of animals, both carnivorus and herbivorus, have been found torn to pieces in territory said to be of the peripheral beasts. The poor animals seem to have been shredded to ribbons by fierce claws and then ripped apart as they were eaten.
General defense believers use againsts critics when questioned how they cannot be seen if not invisibility is the fact that vampires cast no reflection for some reason.