The Tyrant is the result of a human who underwent an infusion of a T-Virus specimen. Weather the original host was alive or dead is unknown. The experiment was a failure, but Wesker sought to use the Tyrant as a super soldier in itself, despite it's raw nature.
Related Threadstyrant - last post by @ Jul 22, 2006
What is Tyrant and Nemesis? - last post by @ Jul 23, 2003
Can you defeat Tyrant on the plane using zero ammo? YES! - last post by @ Jul 11, 2005
The BEST way to BEAT Tyrant in the airplane! - last post @ Jul 8, 2005
Details of The Tyrant - last post by @ Oct 23, 2002