Tyrant R was an experimental platform added to
T-103 Tyrants which grafted cybernetic components onto the creatures; this with an attempt to replace the standard means of issuing commands to a Tyrant by training. The hope with the Tyrant R was to be able to control them remotely by computer, essentially turning them into cyborgs for the lack of a better term.
The Tyrant R was first tested as a weapon by unleashing a barrage of Hunter Alpha B.O.W.s (Bio-Organic Weapons) at it; it easily made short work on any that attacked it despite its electronic components being disabled at the time. As it never saw the Hunters as much of a threat, it made no attempts to eliminate them all - any that simply wanted to escape did so freely.
It's electronics were activated by an Umbrella researcher named
Carter in a Raccoon City laboratory and it was his intention to have it eliminate any wandering B.O.W.s as well as other rogue Tyrants. However the Tyrant R was extremely intelligent and knew that it had an explosive sewn into its body that could be triggered at a moments notice using a handheld detonator device. It conducted its programmed instructions but then it killed
Carter, destroyed a
t-Virus vaccine and knocked another employee named
Linda Baldwin off a high catwalk and subsequently the detonator for the explosive was also destroyed.
Being essentially free from control, it turned to other survivors with the view to kill them all. It pursued them outside of the laboratory and into the greater Raccoon City. Here it began its first mutation and evolved into a much more powerful creature; interestingly it seemed to retain much of its intelligence which was unlike a standard
T-103. However, it would not remain in this form for long as it was soon absorbed by another experimental B.O.W. named
Nyx which had the unique ability to permanently assimilate any organic material into itself - like a biological vacuum cleaner. However, the Tyrant R appeared to be far too strong for
Nyx and after a short struggle between itself and a handful of survivors who were attacking it, the Tyrant emerged fully formed and managed to reduce
Nyx to pure biomass.
Later on or encountered
Ada Wong who had experience fighting T-103s and saw this creature as not so different - although a long battle between the two ensued, Ada came out on top and defeated the creature and then managed to escape. The B.O.W. was regenerating quickly and was about to resume its onslaught only for it to be completely obliterated by a massive explosive which destroyed the entire city. It is assumed that the explosive also triggered the bomb inside the creature as well causing a chain-reaction effect; no amount of superhuman regeneration would withstand that.
