(King's BIO HAZARD2 mythos)
Tyrannosaurus is a genus of dinosaur believed to be long extinct until a B.H.S.T. team discovered one living near a stretch of Great Wall of China which, according to Microsoft, housed all sorts of supposedly-extinct animals.
Thanks to Umbrella's biological weapons experiments, the Tyrannosaurs fed on giant Licker HKs, apparently designed as herbivores. Leon; Microsoft and Baakdo found one in the act of hunting, soon after seeing a giant, winged Mech fight it back.