Blood Briars

Blood Briars are semi-sentient, tendril-like vines, shaped by Void magic and controlled by Delilah Copperspoon and her coven in the The Brigmore Witches and Dishonored 2. Summoned by master witches using the Bloodbriar supernatural ability, they use Pull to ensnare targets, dragging them in and assailing them with a barrage of attacks. If Daud gets too close, a Blood Briar will grab him by the wrist, briefly rendering him immobile. Though they rarely appear naturally, they can thrive after being summoned if they are left unchecked.

The Brigmore Witches
Blood Briars are first encountered within the sewers of Drapers Ward, where two of them grow beneath the machinery in the Water Control Station. They must be eliminated in order to activate the water wheel for the Hatter gang although they will not attack Daud.

They are not found throughout the Brigmore Manor as the gravehounds are, but are summoned by master witches during combat where they can pose a serious threat if overlooked. On the highest difficulty, a Blood Briar can kill Daud within seconds if it manages to grab him.

Delilah Copperspoon and her clones will summon Blood Briars for aid during her battle with Daud at the end of the DLC.

Dishonored 2
During the opening scene within Dunwall Tower's throne room, Delilah summons a giant Blood Briar to restrain Corvo Attano whilst she absorbs his Mark, before dispelling it.

Blood Briars are not encountered until The Royal Conservatory, where Breanna Ashworth and her fellow witches use them along with gravehounds as a deterrent against intruders. They can be easily sneaked past should the protagonist move slowly. Blood Briars can no longer use Pull to ensnare their targets from a distance.

They may also be summoned by higher ranked witches during combat. If the non-lethal option is taken and Ashworth's connection to the Void is severed, the Blood Briars in the level are destroyed.

Blood Briars are later encountered during Death to the Empress, where they grow along the main path within the grounds of Dunwall Tower.

Trivia

 * A pair of Witches within the Royal Conservatory can be heard discussing Lucinda, a fellow coven member who tried to summon the Blood Briar and gravehounds without success. This is because Delilah, like Daud, has little to no control over the powers conferred to her followers through Arcane Bond.
 * While Far Reach with the Pull Enemies upgrade can lock on to Blood Briars, it does not do anything.
 * According to the Dishonored Roleplaying Game, blood briars can also send out barrages of thorns.