Tyrant virus
Binomen Unknown
Average height Microscopic
Sapience Unknown
Aggressivity Extreme
Habitat Hosts
Diet Parasitic
Lifespan Unknown
Subspecies Coming Soon
Status Data Deficient
Behind the Scenes
Universe Resident Evil

The Tyrant virus, commonly known as the T-virus, is the second mutagenic virus discovered by the founders of the Umbrella Chemical, inc.

While the tyrant virus is responsible for the creation of the majority of their Bio-Organic Weapons (or B.O.Ws), the original intent was to create the perfect B.O.W, the Tyrant.


On December 4, 1966 the Progenitor Virus (also known as the Mother or Founder virus) was discovered by Lord Ozwell E. Spencer, Sir Edward Ashford, and James Marcus. These three gentlemen had a certain economic position and decided to begin research upon the virus. Most of the research was carried out by Marcus, as Ashford died in 1968 and Spencer was already occupied by his burgeoning chemical corporation, Umbrella. Marcus had little resources to pool into the investigation, until Spencer agreed to employ him as a researcher and later Director of his corporation's Training facility, putting the vast resources of Umbrella into his hands.

Marcus overbid his hand, greedy for the power to finally invest serious amounts into his research, demanded numerous resources to perfect and improve what he envisioned was his life's work. This led to friction between Marcus and Spencer who, to compensate from the crippling economic demands laid by Marcus, demanded that he create a virus with a 100% effectiveness rate, much to the confusion of Marcus and his assistants, new Umbrella Trainees Albert Wesker and William Birkin.

The Umbrella Corporation used its finances to secretly develop the virus under the radar of international authorities. In time, Marcus further evolved the virus, creating the first effective bio-weapon to be produced in large quantity and be closely studied by the Umbrella Corporation. By adding the virus to leeches, the attributes of both were combined, and the t-virus soon saw the light in 1978.

Though most of the research for the virus took place within the Arklay Laboratory underneath the Spencer estate façade, some eight miles North-west of Raccoon City, and the Umbrella Training facility under Marcus' orders, covered by the American Umbrella offices, Spencer's Umbrella empire in Europe raced against Marcus to adequate the t-virus to create a virus with an even greater destructiveness. Marcus' dreams to overthrow Spencer and his attitude towards the virus as a "money-spinning tool" for Umbrella were never fulfilled, as he was murdered before he could enact them. Birkin came to be known within Umbrella circles as the true creator of the t-virus.

During those years, vast numbers of t-viral strains were developed in the Arklay Laboratory, and tested upon one solitary test subject: Lisa Trevor. For years, she was subject to intense biological torture, which, despite all odds, she survived.

As well, William Birkin, grown conceited as being credited as the creator of the t-virus, spawned a myriad of biological weapons to serve as backup to the virus, to ensure a 100% death ratio in any populace the virus should be released. Among these are the Hunters (created by fusion of a human fertilized egg with t-virus infected reptilian DNA), the Ivies (flowers grown to unnatural proportions and given animal instincts, locomotion and rudimentary defence mechanisms), the Chimera (a mixture between a fly and human given vague humanoid appearance, increased size and mass, improved claws, and better reflexes), the Cerberi (infected dogs - specifically Dobermans), and most importantly, the crowning achievement of Birkin's career for the time: the Tyrant.

Later, Lisa Trevor's body, by now a melting pot of unthinkable disease, had deteriorated to inhuman levels. Noting she was, while not a Zombie, incredibly stronger, slightly more intelligent, and impervious to all damage, Birkin decided to test the NE-α Parasite (by then reputed to kill all its hosts, no matter how strong, in a matter of twenty minutes) in her. The results astounded even Birkin: Lisa's body, by then a hideous amalgam of all viruses ever tested on her, overcame the parasite and absorbed its rejuvenation properties, giving her even more destructive capabilities, greater strength, and total invulnerability to gunfire. Even with shackles she could not be bound. After she outlived her capacity when Birkin extracted what would become the G-Virus deep from within her, he had her killed and disposed of. Though, due to the properties of the primitive G-Virus within her veins, death would not take her away that easily. She would spend the next decade hiding underneath the courtyard.

When the time came in early-1998, James Marcus revived, rejuvenated by the immense power of the first t-virus strains, coordinated into a steady pace by his own DNA and that of his leeches. For more than three decades, the t-virus threat had been averted, but at the time of his awakening, the Arklay woodland was slowly corrupted by the infectious agent. Before long, the Arklay laboratories had fallen. The Research facility was seemingly infected by infected water, causing its employees to fall to anarchy over the relatively long period of time between May 11th and late June, 1998.

The believed abandoned Training facility too, fell. Two umbrella teams sent to evaluate it for re-activation were killed by the creatures from within and outside of the facility.

From there, stories started stemming from the forest; several killings took place and an elite team of paramilitary units, the S.T.A.R.S Bravo team, was sent from Raccoon City to destroy the threat, oblivious to its real cause. Only four of these members, Rebecca Chambers, Enrico Marini, Kenneth J. Sullivan, and Richard Aiken survived the night. All of them ended up holed up in the massive Spencer estate and its adjacent areas, where the next day, the S.T.A.R.S Alpha team entered as well, after suffering a similar fate at the hands of the pack of Cerberi.

Later on, the remaining members of S.T.A.R.S met up at the underground laboratory where the Tyrant T-002 was kept. This Tyrant killed, albeit temporarily, Albert Wesker, and was killed by a rocket blast in the second brawl it offered the remaining S.T.A.R.S.

After the demolition of the manor, the virus sources were thought stopped definitively, but when William Birkin's subterranean laboratories were attacked by Umbrella's Black Ops in September 1998 in an effort to retrieve his G-virus, another outbreak ensued. This infection encompassed all of Raccoon and ended in the forced termination of the entire city. Umbrella was immediately exposed as creator of the virus due to the enormous amount of evidence produced from the scarce survivors, and was shut down.

Still, another outbreak was induced in late 1998, on Rock Fort Island, this time by the revived Albert Wesker and his new organization, the Agency. This ended in the partial demolition of the Umbrella installations there and the total destruction of the South Pole Umbrella Research Center.

Yet another occurred in 1998, this time on Sheena Island; an Umbrella owned "Tyrant Factory". Hundreds of adolescents from across the globe were kidnapped and taken there to be dissected, to retrieve a hormone important for Tyrant development. This infection was caused by the - now mad with power - Commander Vincent Goldman. The island was "sterilized" when the self-destruct system was activated.

Another occurred in 2002 on an Umbrella-owned luxury cruiser, the Spencer Rain, caused by an ex-Umbrella researcher-turned bio-terrorist. All crew and passengers were transformed into Zombies with the virus. The ship was destroyed when it crashed into an island which housed the -also infected- Umbrella Atlantic Facility, and a secret underwater Missile Silo.

Also in this year, a South American group released the virus throughout the surrounding area.

A bioterrorist attack in 2005 India was halted by WilPharma's t-vaccine. This attack was actually planned by a WilPharma researcher, who wanted to demonstrate power of the virus and its vaccine to potential buyers on the black market.

The last known outbreak occurred in 2005, within the Harvardville Airport, where the infection began after a single Zombie entered the building and began to attack people within the building. A small-scale outbreak happened at the nearby WilPharma Corporation bio-dome facility, after a bomb was detonated. Both facilities were eventually sterilized.

Movies History


The blue T-virus of the movies.

The t-virus was developed by Dr. Charles Ashford in order to reverse the inevitable cellular breakdown in his daughter Angela. The virus acts by stimulating pre and post-mortem cellular growth, with the unfortunate side effect of basically killing the host in the process. To counter this, Ashford developed an anti-virus. When the t-virus was used, and kept in check by the anti-virus, Angela could avoid the debilitation that had kept her father confined to a wheelchair.

The effects of the virus in the movies do not differ widely from the game virus. There are a few exceptions:

The rate of infection varies, but is generally much shorter than the games, depending on the severity of an infected person's wounds. In the movies, a severely injured Rain lasts less than two and a half hours, while Carlos Oliveira goes for more than three before showing any outward signs of infection. In both cases, the subject lasts longer in the games. Bio-weapons like the Licker are produced differently in the movies. A Licker is created by direct injection. Similarly, a scratch from a licker can cause mutation. A stronger strain of the t-virus also exists, accidentally created by Sam Isaacs when he treated zombies with a serum derived from the blood of the Alice clones. The resulting Enhanced Zombie carried a much stronger viral load; once bitten, even multiple doses of the anti-virus could not remove the infection.

T-virus Infection

By Inhaling

This process of infection is only seen in the 2002 film Resident Evil, in which the initial infestation of the Hive is caused by the release of the T-virus into the atmosphere. According to the film, there is an airborne T-virus strain.

However, the T-virus is not airborne in the games.

Human Infection

Human infection can take as long as a week, or even a few minutes before transforming the host into a zombie. The time difference seems to depend on the victim, along with the method of infection (i.e. injection, bite...etc).

Secondary Infection

The stages of infection from drinking infected water usually last between a day and a week.

The stages of infection are the following:

  1. The victim's skin begins to rot, slowly, causing unbearable itching. Necrosis occurs afterwards.
  2. The rotted skin eventually falls off in lumps. Deterioration of the brain occurs, causing mental instability. If in groups, this can cause cannibalism.
  3. The victim is now considered a zombie, reduced to (and relying on) only its primal instincts. By now the zombie has a level of hunger that cannot be quenched by normal food. Therefore it only craves and hunts for flesh, constantly trying to satisfy itself in vain.

Zombie-Human Infection

This form of infection lasts between minutes and a day, depending on many variables including...

  • the immune system of the victim.
  • the amount of T-virus initially contracted.
  • If Medical objects such as a First Aid Spray, an Anti-Virus Pill, or a Herb are used, the rate of infection is slowed down temporarily.
  • Open wounds allow the T-virus to spread quicker.

Leech-Human Infection

Being Leeches, they feed via sucking the blood of creatures, allowing the Leech to infect faster. Between the attack on the train and the discovering of the zombies by Rebecca Chambers, is would take less than 2 hours, maybe even minutes. Sometimes the leeches will stay on the body making a 'Leech Man' which will turn into a Zombie within minutes, with the Leeches still hanging on.

Cerberus-Human Infection

Cerberi always travel in packs. Due to their canine instincts, they will all eat the target. Due to packs being at a maximum of 10-14 (explained in files), it would be more likely of the human dying and their body being too damaged to resurrect.

Nyx-Organism Infection

The Nyx project always absorbs its prey into its body, limbs can be formed from absorbed victims. None of its victims have a suitable enough for resurrection if freed.

Known Antigens


The anti-virus.

There are four known serums that will cure those infected by the t-virus, but only in its earlier stages, before it becomes completely active.

Umbrella Medical Vaccine

The first is an unnamed vaccine developed by Douglas Rover of the Umbrella Medical Service at Raccoon General Hospital as a last-minute effort to halt the rapid spread of the t-virus. However, most of the hospital's staff had already succumbed to infection before the vaccine could be properly produced even in small amounts.

This vaccine could be cultivated by using a specialized synthesizer and inserting a medium base into the system, then combining the necessary chemicals using the control panel. The exact components that were used to create this prototype are unknown - as most of the documentation regarding its production were either stolen by Nicholai Ginovaef or destroyed after he demolish the hospital with C-4 charges - taking with it any evidence of the Umbrella Corporation's involvement with the hospital in the process.

However, Carlos Oliveira was able to create a single dose of the vaccine for Jill Valentine (who had been infected by the NE-T Virus, a variant of "t") and managed to escape moments before the hospital's destruction. While the vaccine apparently did not immediately cure Jill of the Virus, it did send it into hibernation, until it eventually died out. It also apparently created powerful anti-bodies within Jill, making her immune to most other viruses, even possibly Uroboros.


Daylight was developed by Greg Muller and Peter Jenkins of the Raccoon University. The actual ingredients for Daylight are:

  • T-Blood: a blood sample of a t-virus infected creature, namely Thanatos;
  • V-Poison - a sample of poison from an infected Wasp;
  • P-Base - an unknown chemical liquid that requires preparing before being mixed. Once all the ingredients have been collected, they can be mixed together in a special chemical mixer. The mixture takes about five to seven minutes to make and thirty seconds to one minute to duplicate.


"AT1521" was developed by the research team operating from within Umbrella's official Raccoon City facility. Linda and Carter, surviving developers of the vaccine returned to the facility on October 1st, 1998 to retrieve it in hopes of wide-spread production of the vaccine.

The exact details of the serum itself are unknown due to the short role it played in the storyline (the sample being destroyed by the rampaging Tyrant T-0400TP not long after its initial appearance). However, Linda did remember the reagent's base, and thus was able to remake a sample.


The fourth is an anti-"t" agent known as the t-vaccine created by WilPharma. Unfortunately, most of the samples were destroyed by Frederic Downing right after the Harvardville Airport t-virus outbreak, and the last t-vaccine sample was taken by Downing so that he could sell it to bioterririst General Miguel Grandé along with the t- and G-virus samples, but he was caught by Claire Redfield and Leon S. Kennedy before he could sell it. It is possible that the US Government used the last anti-virus sample to produce more in case of future outbreaks.


There are also some prototype antibodies for the t-virus used by the UBCS]. They were only mentioned in a pocketbook kept by a deceased UBCS mercenary in the St. Michael Clock Tower. It should be noted that no "Zombified" UBCS members were encountered in the Clock Tower.

Regular Anti-viral pills can slow down t-virus mitosis temporarily.


There is one seen only within the movie world, called Anti-virus. It is a dedicated, engineered anti-virus created by Umbrella. This one is only effective if the patient does not have a large amount of the t-virus in their bodies, or the infection is caught in the early stages. This one was shown in the first and second movie but its effects were different and was developed by Dr. Charles Ashford for his daughter, Angela.