Uroboros was a virus named after Ouroboros which is a
Snake that devours it's own tail, commonly shown as an infinity symbol. It was created by
Albert Wesker as a method to dispose of all humanity apart from the strongest. The virus horribly killed anybody infected that did not fit it's required genetic profile. However, for the ones that did - they were to become superhuman in terms of strength and also mentally.
The virus itself is administered as a bright pink fluid, and one dose is approximately 7.5ml.
At first the virus was too selective - it would have killed almost everybody; a new strain was created using
t-Virus antibodies taken from
Jill Valentine which was less potent, but still extremely selective.
More tests began using thousands of test subjects, and eventually
Albert Wesker himself became infected. He was selected, survived and grew stronger and more intelligent. However, all the others were rejected.
Rejection is an intense reaction. The infected mutate rapidly and out of control. Every cell in the body is overtaken by the virus, and tentacles sprout from all over the body, absorbing any organic material in the area including the host body. If no more organic material can be found, the host retains a vaguely human shape, with features such as eyes, arms and legs still discernible. There is no apparent upper limit to how much biomass the virus can absorb, given enough material for it to absorb, and the more which is absorbed, the less human it becomes and more plant-like.
The tentacles are joined by bright orange organs, which serve as a weak point, as if these anchors are destroyed, the tentacles will (briefly) detach. The other weakness which Uroboros has is against heat or fire. Any heat source is sufficient to damage it, however small.
Being compatible with the virus is an entirely different story. No outward mutation occurs - the host becomes stronger, faster, more resilient and can heal almost instantly. The only giveaway is the eyes change from human-looking to
Snake-looking.
Albert Wesker one of the only documented compatible host which survived long enough. He needed regular injections to keep him strong but it is not clear whether this is typical as he already was infected with a form of
t-Virus.
Also infected with the virus was Neil Fisher, who did not appear to be compatible and was later killed by Moira Burton. Alex Wesker also infected herself with the virus but again, was killed soon after. It is unclear if she was considered compatible as Alex was already horribly mutated at this stage.
Fun Fact: A similar creature to Uroboros appeared in a rejected, earlier version of
Resident Evil 4. Named Black Fog, It was a mass of dark, wet tentacles that were surrounded by fog. It was likely cut from the final game as the hardware was unable to animate it believably.
