The Weevils were a race of savage alien humanoids that could be found in Cardiff, presumably due to the Cardiff Rift.
Physiology and characteristics
Weevils were roughly humanoid in shape and size, but are a bit taller and have flattened faces with many sharp, fang-like teeth. Though faster and stronger then Humans, they aren't extraordinarily powerful and can be injured with electricity, brute force or by Torchwood's anti-Weevil spray. Weevils are a highly adaptable species, being able to develop a resistance to the spray that the Torchwood 3 staff had developed. (TW: Combat) They were unable or unwilling to communicate with Humans. (TW: Everything Changes)
Weevils had mild telepathic abilities and couuld feel strong emotions from other Weevils far away. This allows them to develop a basic social order and to mourn the pain and loss of other Weevils. (TW: Combat) When the Cardiff rift fractured, Weevils in captivity in the Hub's basement howled, seemingly with fear, leading Jack Harkness to speculate that the Weevils had some degree of time sensitivity. They could also detect the illusions created by Bilis Manger. (TW: End of Days) The Weevils appeared to be scared of the sleeper agents in a manner that Jack had never seen. (TW: Sleeper)
The Pharm was able to extract a pesticide and a powerful defoliant from the Weevils. (TW: Reset)
History
Origins
Though the Torchwood Institute did not know the native time period and/or homeworld of the Weevils, an uninformed layperson, Mark Lynch believed, however that the Weevils may be descended from Humans, at a point in the future when "all that is left is rage" (TW: Combat). However, early Torchwood Research believes they aren't derived from any native Earth species. (torchwood.org.uk)
Interactions with Humans
The Weevils have been arriving on Earth for over a thousand years, and Torchwood 2 believes they have been seen in the such places as the sewers of 4th century Byzantium and 1930s New York (although this was more likely a pig slave infestation, DW: Daleks in Manhattan). The Torchwood Institute had known about them since the 1950s. (torchwood.org.uk)
In 1497, via a Resurrection Gauntlet, a powerful being, Durac, identified with and embodying death itself, entered the Universe. The Weevils worshipped it. Humans associated Weevils with death and in, woodcuts, illustrated a being intermediate between the popular image of the Grim Reaper and the Weevils, intimating that the Weevils had, perhaps, inspired the Grim Reaper image. (TW: Dead Man Walking)
21st century
They have been more commonly seen in 21st century Cardiff, where hundreds lived in the sewers. They generally ate the most common resource in the sewers, though they occasionally venture out to feed on Humans. They have a distinctive hunting style, always going straight for the kill by biting and ripping at the throat and body. (TW: Everything Changes, Countrycide)
One of the jobs of the Torchwood 3 is to capture these Weevils and put them in storage cells in the lower level of the Hub. (TW: Everything Changes onwards). Several cages are kept for storing these rogue Weevils and anti-Weevil spray and handcuffs are stored for this purpose. (TW: Everything Changes) The Weevils were also captured by Mark Lynch for his "Weevil Fight Club", where Humans battled against Weevils to deal with their pent-up rage. (TW: Combat)
- Though seemingly unintelligent, all Weevils have been shown wearing what look like black synthetic fabric pajamas. Whether they steal them or make them themselves is unknown. At least one, however, wore an outfit with the words "Torchwood" on it, suggesting that Torchwood 3 clothes them after they capture them.
When the Cardiff rift fractured, more Weevils than ever appeared on the streets, making Torchwood 3's task of rounding them up even more difficult. (TW: End of Days)
- When the fractures sealed up and the other temporal refugees returned home, we do not know if the new Weevils vanished as well.
Unknown to Torchwood 3, the Pharm had also captured at least one Weevil as part of their self-assigned mission to exploit the unique qualities of alien species for use in biomedical research. As noted above, the Pharm discovered the Weevils useful as far as developing new kinds of defoliant and pesticide. (TW: Reset)
A large group of Weevils inhabited St. Mary's, an abandoned church, accumulated odd Human items and guarded a Resurrection Gauntlet. (Presumbably one of two, the other having been destroyed by Torchwood 3.) When Durac returned and possessed the undead Owen Harper, Weevils followed and did reverence to him.(TW: Dead Man Walking)
