Haemovore

The Haemovores, or Homo haemovorax, were a species of vampire-like creatures that served Fenric, existing as possible future of humanity half a million years in the future, mutated by the chemical slime of a polluted Earth. Their time stream was accessible to time travellers. (PROSE: Goth Opera)

Biology
Haemovores were a species of vampire-like humanoids who evolved from humans. They fed on the blood of humans, though they could also survive in sea water, which had a similar salt content.

The Haemovores had enormous strength and power, and could climb sheer surfaces with ease. They were resistant to bullets, and could only be killed by a stake to the heart. Also, Haemovores had razor-sharp claws, which they used to kill people. Haemovores could even weld metal with their hands, and older Haemovores built up armour made of metal they collected and melted together. The Haemovores could be stopped with a psychic barrier, which in humans was created by the mental processes associated with strong faith; the Doctor could create this barrier at will. In the presence of the barrier, the Haemovores often responded with ear-splitting shrieks.

Haemovores were known to only hunt in the fog or mist.

Due to their similarities, they were often mistaken for actual vampires.

The Haemovores communicated with each other telepathically. This could be detected by telepathic humans. They could also telepathically control humans, making them easier to feed on. They were all controlled by Ingiger, who could kill them with a thought. (PROSE: The Curse of Fenric)

Life cycle
The Haemovores started life as humans, who were changed by other Haemovores. At first, the only signs of change were pale skin, large red lips and sharp claws. They still had their minds and memories, but a more feral mindset. As they aged, their appearance started to change: Their skin grew slimy and wrinkled, their eyes were swollen shut and their mouths turned into suckers for feeding. After a century, they were completely transformed into Haemovores.

After being killed, they would rapidly decay into charred bones and slime. (PROSE: The Curse of Fenric)

History
The Haemovores evolved on Earth circa 500,000 AD, after the planet was ruined by industrial waste. They lived under the chemical swamps, in the saline solution of the ocean, consuming plankton and sometimes ganging up on a great whale to feast. (PROSE: Goth Opera) The last Haemovore was Ingiger, who believed himself the last living creature on Earth. Fenric brought Ingiger back in time to Transylvania some time after the 10th century, where he fed on the Vikings who had taken the flask containing Fenric. (TV: The Curse of Fenric)

He and the Haemovores followed them to an island in the North Atlantic where the Vikings, Ice Warriors, Twelfth Doctor and Bill Potts faced off against the Flood, who the Doctor knew from his personal past. The Doctor realised that Fenric intended to replace the Haemovores with the Flood and convinced one to form an alliance for mutual benefit. Using a weapon stolen from the Ice Warriors, the Haemovore detonated a volcano and destroyed the Flood on Earth. Fleeing the island, the Haemovores continued their pursuit of the surviving Vikings. (COMIC: The Wolves of Winter) and after they were killed by the pirate Hemming, followed him to Maiden's Bay.

Though Hemming and all his men were killed by the Haemovores, Hemming had buried the flask beneath St. Jude's Church where they could not get it. Instead, the Haemovores were forced to wait. In the mid 19th century, a girl was fed on by the Haemovores of Maiden's Point. This story would be told to Bram Stoker. It would be part of the inspiration of the story of Dracula. In 1943, a squadron of Soviet soldiers were sent into Nazi-controlled Romania. All but one man was killed by Haemovores, though he was mentally scarred by the experience. Captain Sorin and Sergeant Trofimov were sent in with a rescue team, though they were only able to find the one survivor. (PROSE: The Curse of Fenric)

Six months later, the Haemovores in Maiden's Bay were awoken by Fenric to attack the Soviet and British soldiers as part of a trap to defeat the Seventh Doctor. Once they had served their purpose in this plan, Fenric ordered Ingiger to kill the Haemovores with a thought. Using the poisons made by the nearby base, Fenric intended to pollute the world, causing the future that created the Haemovores. The Doctor was able to convince Ingiger to betray Fenric; the Ancient One killed both itself and Fenric by going into the isolation chamber with Fenric and releasing a poison. This prevented the Haemovore's formation. (TV: The Curse of Fenric)

The Haemovores made a lasting impression on the Doctor and Ace, as they would recall them in later travels. (PROSE: Cat's Cradle: Time's Crucible, Cat's Cradle: Witch Mark)

Behind the scenes
Andrew Cartmel based the Haemovores on aquatic vampires that appeared in an issue of Alan Moore's run on Swamp Thing.

The creation of the Haemovores appeared to be a predestination paradox, Ingiger releasing a poison on Earth that would lead to the Haemovore in the future, where he will be the last living thing on Earth before being drawn back in time to release the poison. So after the Doctor's defeat of Fenric, this future may not have been definite. However, the novel Goth Opera has since established that this is only a possible future.

History of Mankind according to Doctor Who claimed that the Haemovores were a part of the familiar, linear timeline of the Doctor's universe, placing their existence on a polluted Earth abandoned by humanity between the years 5000 and 10,000. It is further stated that the Haemovores went extinct as the planet's ecological balance was restored, leaving it to be reclaimed by humanity.