Weeping Angel

Don't blink. Blink and you're dead. They are fast. Faster than you can believe. Don't turn your back. Don't look away. And don't blink.'

'In the dark of the night the angels came, to take my dear child away. Off to rest may my daughter go, taken by the Angels of Stone.'

Creatures of the Temporal Plane:

Thought to have been an accident of creation, beings never meant to exist the Weeping Angels are the stuff of ancient legends, and children's nightmares.

Born of the Temporal Plane where time ebbs and flows in unusual and often unpredictable ways the Weeping Angels have evolved to control these currents of time when in their home realm, allowing them to manipulate time as they see fit.

However outside of the Temporal Plane things are very different, the flow of time there is fixed and fixed time is near impossible for Weeping Angels to survive in as they find themselves nearly frozen, only able to move at a rate imperceptible to most other creatures, causing them to slowly starve to death.

However being both smart and cunning the Weeping Angels realized that even outside of the Temporal Realm they still held a strong connection to their home plane of existence, and through this realization they learnt how to manipulate the flow of time around themselves to move, at least to the outside observer, with lightning fast speeds. This make them vicious and incredibly effective hunters.

However they do have one crucial weakness.

Temporal Restrictions:

When a Weeping Angel is being directly observed, they become locked to the flow of time as it exists in the realm of the creature observing them.

This results in observed Weeping Angels losing the ability to manipulate time around themselves causing them to appear as nothing more than statues, seemingly not moving at all. When in reality they are simply moving so slowly that it is imperceptible to most.

Apex Hunters:

The Weeping Angels are predatory creatures that feed off of the life energy of living beings. However, to the detriment of the species they do so far to efficiently, and over endless generations the availability of food in the Temporal realm dwindled away until there was no longer enough food to sustain them, and so they ventured into the material plain seeking a new source of sustenance.

However due to their temporal restrictions they needed a new way to hunt. Over endless generation of angels born into the temporal plane they evolved a the ability to to make all who gaze upon them do one simple thing; blink.

This simple ability allows them to free themselves from their temporal restrictions, giving them the opportunity to close in on their prey and feast. 

Temporal Lock:

The Weeping Angels preferred method of feeding is brutal but effective. Upon laying an attack upon their foe they appear to petrify their prey, locking them in a prison of stone. Now whilst this is true this description is also incomplete. In reality the soul of their petrified victim is sent to the Temporal plane where whole years of their life go by while mere seconds pass in the material plane. With their victims locked in a petrified state even in the temporal realm, the Weeping Angels feed off of the life force being expended as their victims age, a single strike stripping years from their life.

Upon return to the material plane the victim is released from their stone confines where they must come to terms with the years of their life they just watched go by. The one small solace that their victims may have is that the minds of those from the material plane are unable to fully adjust to the sudden and dramatic shift in the flow of time. This results in the time spent in the Temporal Realm being difficult for a person to remember