Vampirism

A unique form of corrupted undead through the use of the corruption and necromancy, ressurecting corpses that die to the magical virus into superhuman barely-sapient, tribal, cannibalistic variants of their prior selves. Pulled from the Tir-Falora genetics, against the clan's will during its early years. These creatures, nicknamed "Nosferatu" by the Firstborn have a never-ending hunger for human flesh and blood, completely lacking souls as animalistic, feral creatures.
This was used as an emergency bio-weapon by the Firstborn during the First Age dropped on human settlements of escaped slaves through rebellion in the hopes of sending them into a cannibalistic rage and devour themselves. Due to this rage Vampires will attack anything in their way, but they will only ever actively hunt and eat humans, or being that hold a significant amount of human blood. Vampirism affects all living creatures including animals, humanoids, and plantlife. But Firstborn are immune to the virus, and Dragons are highly resistant.
When this bio-weapon was unleashed during the fall of the Septem Diademata, transforming all of them into the banished Torquenti Terram, many locations across the world began to mutate with the virus effect plantlife. This spread is often affiliated with the Daemon due to the corrupted, black tar-like sap of the plants, when it has little to nothing to do with it.
Instead, it is spread due to these bio-weapons being unleashed from a ruin of the Firstborn, or, from direct influence of a Torquenti Terram. Instances of plantlife being effected by Vampirism is often known as "Barkbite", as the mutated plants will become flesh-like. Unnatural abberations of life, twisted and corrupted into semi-sentient variants of their original plant forms that hunger for the flesh and blood of humans.
Notably, the base of the virus effecting plantlife instead of humanoids appears to cause several alterations to the corruption. Lacking the increase in power and ability, the plants are no more sturdy or potent than their normal counterparts, simply hungry and maleviolent. In return they do not suffer the weakness to direct sunlight, and it causes them no harm, but nor does it provide them with nutrition any longer. A plant suffering Barkbite will only grow after feeding on human flesh and blood.
Due to their lack of proper blood, the virus also mutates the sap into something more akin to black tar. With a scent a mixture of tar, blood, and oil. This liquid is highly flammable and is comparable to ignighting a fossil fuel, which has caused many a problem when humans attempt to burn the Barkbite forestry down. Leading to a massive chain explosion, often killing those that attempted such.
Though uncommon, large sections of plantlife that is under this effect often lead to the deaths of hundreds of humans in painful ways. Due to this, they are often viewed as haunted, and are filled with angry, maleviolent, mad, but generally individually weak spirits.