"The very first Werewolves… a dangerous and infectious breed… created from Marcus’s own flesh and blood: His twin brother, William. These were raging monsters, never able to take human form again."- Andreas Tanis, describing the Werewolf species.
Werewolves are once normal humans who were infected by the first Werewolf or another of his victims. Unlike a secondary breed descended from them, called Lycans, this early breed were savage beasts incapable of thought or reason and could only take human form again after death.
Werewolves display a number of greatly enhanced physical attributes. As with their rivals, the Vampires, Werewolves are immortal. For example, the original Werewolf survived over 800 years of captivity with no food or water in what appeared to be a type of hibernation. They possess enhanced senses of smell, hearing and sight that are superior even to those of wolves, not just humans. Werewolves are also able to sense Vampires in close proximity to themselves and possess physical strength, durability, reflexes, and speed superior to those of most Vampires, and can break through solid concrete walls.
Werewolves possess superb physical resilience and remarkable regenerative abilities, however, their recovery abilities are hampered by the presence ofsilver in their bodies. It is mentioned in the first film that silver is fatal if it penetrates the internal organs. Silver is the Werewolves’ only weakness, as they seem to be violently allergic to it. A new variation on this is the use ofSilver Nitrate Bullets to inject the silver directly into a Werewolf’s bloodstream.
William Corvinus’s form of lycanthropy is the most primitive, and also the most powerful. He has the most lupine features, with a long muzzle and pointed ears, giving him a marked resemblance to a real wolf. He is also far larger than his offspring. William was initially born as a human, however, he was bitten by a wolf, causing the Corvinus Strain he had been born with to mutate, making him a Werewolf. William is the most savage Werewolf seen, with an insatiable appetite for rampage. He is unable to revert to his human form, something his father attributed to his uncontrollable rage, and remained in Werewolf form for the rest of his life. Unlike later Werewolves, he has a full pelt of fur all over his body. It should also be noted that while every other Werewolf seen in the films has black or gray fur, William’s is white. He also has solid white eyes.
In Underworld: Evolution, the 1st generation Werewolves turned by William Corvinus before he was captured and after his release are not as hairy as he is, and their appearance resembles transformed Lycans. InUnderworld: Rise of the Lycans, the wild 1st generation Werewolves are completely covered in fur and their appearance is much more wolf-like, to the point they look almost identical to William, albeit physically smaller and black instead of white. This suggests that there is either an inconsistency in the designs of Werewolves in the Underworld series, or 1st generation Werewolves develop more wolf-like features over time after the initial transformation.