The Tyrant R was equipped with various cybernetic components. It could be programmed for various objectives, and was outfitted with a small, but powerful explosive in its neck. Its durability was far greater than that of other Tyrants, and even a rocket launcher would only knock it unconscious, rather than blow it to pieces.
Prior to the Raccoon City Destruction Incident, Hunters were being created in large numbers (via the Nursery, or by transportation) to combat the Tyrant R in a number of strength tests. However, the Tyrant still hadn't been activated by the time of the Outbreak, and the Hunters escaped.
The Tyrant was activated at the early hours of October 1st by Umbrella scientist Dr.Carter to combat the renegade Hunter Rs lost in the facility. Just prior to the escape of the survivors in the lab, the Tyrant became self-aware, killing Carter, destroying the t-Virus vaccine and knocking both Linda and the detonator for its internal bomb off a catwalk.
After chasing David King and Linda through the ruined city and mutating into a more powerful stage, the Tyrant arrived at the highway overpass and was ready to attack David. Suddenly, Nyx grabbed hold of and absorbed it into its body. Nyx was destroyed by David and it was set free again. It then confronted Ada Wong, another fleeing survivor, who defeated it with ease, identifying it as "clever, but predictable". Ada killed the monster for good.