"Uroboros... It's not death... it's power!" — Neil Fisher while mutating

Uroboros (ウロボロス uroborosu?) was a Progenitor-based RNA virus developed by Dr. Albert Wesker and others at TRICELL, with the intent of using it as a tool for a eugenic plan envisioned by Albert himself. The virus was also used by Dr. Alex Wesker to create bio-weapons. As of 2011, there is no known vaccine for Uroboros. The virus is named after the Ouroboros in Greek mythology, which is a snake or snake-like creature that consumed itself.