The Weeping Angels, also known as the Lonely Assassins, are a series of predatory creatures from the television series Doctor Who resembling stone statues.
They were introduced in 2007 in the episode known as Blink before returning in 2010's two-parter The Time of Angels and Flesh and Stone before making their final return in 2012's The Angels Take Manhattan.
The Weeping Angels are described by the Doctor as "old as the universe (or very nearly), but no one really knows where they come from." He also describes them as "the deadliest, most powerful, most malevolent life-form ever produced."
Weeping Angels are unusual as predators in that they neither kill nor directly parasitize their prey. Their usual mode of feeding is to make use of time paradoxes - with a single touch, a Weeping Angel can send a person into the past to a point before his/her own birth, and can then feed off the "potential energy" of the years which that victim would have lived in the present. The Doctor describes the Angels as "the only psychopaths in the universe to kill you nicely" because their victims are otherwise uninjured and may live out their lifespans in the past.
In their usual form, Weeping Angels resemble silent human-sized stone statues in the form of winged angels in draped clothing (such as might appear as tomb statuary in a Victorian graveyard). Apart from the wings, their standard form appears to mimic Earth humans (two arms, two legs, two eyes) even when they are infiltrating worlds on which the inhabitants differ from this form.
Generally, their facial features are bland and serene and their proportions human-normal. However, as they close in on more aware victims they transform to a more horrific, bestial and demonic aspect with wide-open mouths, vampiric teeth, and clawed hands. In the episode "The Angels Take Manhattan", another form of Weeping Angel is shown, the cherubim.
Unlike the Weeping Angels, the cherubim are not silent, making a childlike giggling and having audible footsteps. It is not explicitly stated that these are young Angels, but they are referred to as "the babies". It is also implied that Angels can mimic the forms or dimensions of a broader range of statuary if required: in "The Angels Take Manhattan", one Angel takes the form (or hijacks the existing form) of the Statue of Liberty (manifesting as a full-size Liberty with Weeping Angel features) and the final moments of "Blink" suggest that any statue might be a disguised Angel.
When they are not being observed by another being, Weeping Angels can move very quickly and silently. Their phenomenal speed allows them to close distances of meters literally in the blink of an eye. However, when they are being observed they become "quantum-locked", occupying a single position in space and becoming stone. In this state, they are frozen and difficult to destroy.
They cannot suppress this reaction. If two Weeping Angels were to look at each other at the same time, they would be trapped in stone form until an outside force moves them apart. To prevent this, they often cover their eyes while moving, which makes them look as though they are weeping. When stalking a victim, Angels will generally take advantage of their speed to avoid being trapped in the quantum lock.
Weeping Angels are very physically strong, although they rarely physically kill a victim since this wastes the time-potential energy which the Angels would otherwise consume. One exception to this behavior is when an Angel or group of Angels wishes to communicate with other beings - in these instances, they select a victim and snap their neck prior to "rearranging the brains" for their own purposes; the Angels are then capable of speaking and conversing via their victim's voice and senses.
In the episode "The Time of Angels", a soldier of the Church nicknamed "Angel Bob" suffers this fate, becoming the "voice" of a group of Angels and explaining their motives and thoughts to the Doctor before disappearing in the rip in the fabric of time and space.
Weeping Angels appear to have little culture or motivation other than those serving their basic predatory requirement of gaining energy. The Doctor has described them as the loneliest beings in the universe since their quantum-lock reaction makes it impossible for them to socialise with other creatures. However, Angels are capable of communication, as they often work in groups and clearly communicate with each other.
On those occasions when they have chosen to communicate with their prey or foes (using the gruesome proxy method mentioned above) they have demonstrated a cold and impersonal intelligence, but exhibit no empathy and no emotions beyond hunger, determination, and occasional predatory sadism. While Angels can recognise individuals in other species when the situation requires it, they themselves speak collectively and appear to have little or no concept of themselves as individuals.
Weeping Angels prefer to take their energy from live victims, but if required, they can drain other forms such as that from electric lights (as seen in "Blink") or other electronics. In "Blink," the Angels attempted to steal the Doctor's TARDIS after trapping him in the past. The engine of the vehicle contained enough time energy to feed them forever, but The Doctor stated that the possible damage they could cause "could switch off the sun".
Without power, an Angel will start to decay and revert to a stone state even when not being watched. While still initially capable of movement, its speed will also be extremely hindered when close to a starvation point (as seen in "The Time of Angels"), with its range lessened from meters to a partial step.
The effects of starvation can be undone by providing the Angel with energy, but it is implied that Angels can no longer acquire energy themselves in this state. A starving Angel becomes less and less active, and if dormant for too long will erode as a stone statue does, or even lose its physical existence altogether (although it can still exist in an image-based or conceptual state).
Weeping Angels have also exhibited a startling ability to project themselves through images, suggesting that they are as many conceptual entities as physical ones. A warning in an ancient book on the Angels, found by River Song, states that "that which holds the image of an angel becomes itself an angel".
Using this ability, the Angels appear to be able to hijack both audio-visual equipment and organic memory. In "The Time of Angels", an Angel trapped in the vault of the starship Byzantium took advantage of a video screen which was playing footage of it elsewhere in the vessel: the creature escaped by overriding the screen controls and nearby electronic equipment, took over the screen, and passed through it to physically manifest in another location.
Weeping Angels can also imprint a mental image of themselves into a person's mind by looking straight into their eyes: the image then gestates and takes over the person's body to manifest as a new Angel. Amy Pond was infected in such a manner where an involuntary verbal count-down indicated her remaining open-eyed moments as a human.
She was able to suspend the Angel's gestation (but not eliminate it) by closing her eyes, refusing to let it breach the 'filter' of her optic nerve. In the novel Touched by an Angel, a starving angel is reduced to the point where it no longer has a physical being, and instead exists in the image viewed by cameras.
As such, whatever is within the sight of the camera is within the range of the angel which retains fast movement, but at the cost of range. Normally, as in "The Time of Angels", the Angel image would walk right out of the screen; but when it is starving, it cannot do so. To stop movement, simply viewing the screen is enough to lock the angel.
The Surgeon stories
The Weeping Angels make just one appearance in the story Strategy of a Surgeon where despite being quantum locked they now make an alliance with the sorcerer Azhar Namin who is actually the renegade Time Lord known as The Master. In this form, the Angels almost take on the form of any statue in Egypt and he plans to use them to take over the world.
The Angels are also shown in a more powerful light in this story as well, for example when they touch disgraced politician Asma Benyamina they actually send her to a bazaar that Azhar uses as a cover and later send Ghazal Rashidi there as well where they are used as guards on her. Later, the Angels grow more and more powerful to the point where even when they are observed they still move and even though they cannot be destroyed, one of them is smashed to smithereens by Majid Bashar. Once The Master has been defeated, the statues that became Angels return to normal whilst other Angels disintegrate.