The Host

A Human infected with alien cells, the Host could change from Human to lupine form.

History
The Host was derived from an alien entity whose transport fell to a rural area of Scotland in October 1540 (visittorchwood.co.uk, TS: Tardisode 3, DW: Tooth and Claw). It had landed in St. Catherine's Glen, near a monastery. (visittorchwood.co.uk, DW: Tooth and Claw) The monks took the craft back to the monastery with them. (visittorchwood.co.uk)

There, the Doctor theorized, the monks cultivated the few cells of the entire that had survived, until they had found a host bodies. The monks themselves changed into an evil cult called the Brethren, which worshipped the alien. They kidnapped young boys to serve as host bodies for the cells. (DW: Tooth and Claw)

From then on, locals feared what they called The Howling (Torchwood House website) when the werewolf would roam the moors and kill some livestock and sometimes humans. (visittorchwood.co.uk, TS: Tardisode 3)



Eventually, in 1879, the Brethren arranged for Queen Victoria to be diverted to the nearby Torchwood House where the current host would infect her with the wolf cell, leading to the creation of the "Empire of the Wolf". The plot was thwarted by the Doctor and Rose Tyler, who used a telescope constructed by Sir George MacLeish as a weapon against the werewolf. The telescope was in actuality a gigantic light amplification chamber, and using the Koh-i-Noor diamond as a focusing element, struck the werewolf with enough moonlight to dispel it from the planet. It is unclear, however, if Victoria was indeed infected in the end. (DW: Tooth and Claw)

Biology and characteristics
The Doctor described it as a "lupine wavelength haemovariform" (otherwise known as a werewolf) surmised that only a single cell survived, which was then incubated in various hosts via biting them, passing down through the centuries until it matured.

As a Human, the Host had completely black, inhuman eyes. In lupine form it had red eyes, unlike that of a normal wolf, which can range from brown to blue. The infected Human would turn into a werewolf whenever it was exposed to certain wavelengths given off by the Moon, though too much moonlight would overload its system. Its lupine form was of a brown-furred therian (or bipedal werewolf), having large hands with long yellow claws and snapping teeth, its legs were digitgrade.

It was nearly twice the size of a Human and had increased strength, resilience and speed. Mistletoe would cause burning and twitches when the werewolf touched it. This might have been a conditioned response deliberately created by the Brethren or a physical allergy. It's unknown what affect silver would have, since none was used on it (Though when faced with it the Doctor did ask if anyone had any silver bullets, implying it may have an affect). It was also colourblind, but had a stronger sense of smell to compensate.

The werewolf was also able to sense the Bad Wolf in Rose. (DW: Tooth and Claw)


 * It is unknown how he did this, but the message may have accidentally been sent down through a future timestream.