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Resident Evil Wiki
Prime universe
(Capcom's primary storyline)

"Too much growth weakens an organization, what should be important becomes overshadowed by greed! Mass production?!? Ridiculous!!!""
— Greg realizes Umbrella intends to mass produce Thanatos.

Dr. Greg Mueller was an Umbrella researcher who is known for his 1998 rebellion against the company.


Dr. Mueller worked at the Umbrella R&D Center in Raccoon City.[1] He was already involved in the t-Virus Project in 1993, when he was the banker in an illegal human research trial conducted at a hospital in the Arklay Mountains,[2] wherein patients were infected with a t-Virus variant with anti-carcinogenic properties. Alongside his work with Umbrella, Dr. Mueller also worked at Raccoon University. In 1996 he was able to use a student, Yoko Suzuki, in t-Virus trials. He thereafter performed an operation on her to affect her memories, an action that took until October 1998 to reverse.

With Raccoon University lying on top of unused facilities, this became a prime space for research and storage of bioweaponry, and it was here that the "Thanatos" began development as an experimental next-step in research following the mass-production of the T-103 series. Dr. Mueller objected to Umbrella's interest in cloning Thanatos for mass-production in August 1998,[3] and began working against the company. Partnering with Dr. Peter Jenkins, a Raccoon University professor, the two developed a vaccine effective even against Umbrella's modified ε strain, which was dubbed "Daylight".[4] To cover his tracks, he told Dr. Jenkins that he was a former chief researcher for Umbrella and was smuggled a sample of t-Virus by a colleague still in the company.[4] Rather than use it to treat the at-then slowly expanding viral outbreak within the city, Dr. Mueller wanted it only as leverage against Umbrella - to leave him and Thanatos alone or he would effectively destroy the t-Virus Project.

After the modified ε strain entered Raccoon City's drinking water, tens of thousands mutated into Zombies within hours. Drs. Mueller and Jenkins remained in the university while their colleagues succumbed. On Thursday 1 October, Dr. Mueller executed Dr. Jenkins to tie-up loose ends.[4] Dr. Mueller, aware that Umbrella would take advantage of the outbreak to send an armed team after him, decided to activate Thanatos,[3] and gave it clear instructions. The B.O.W. responded to orders by massacring a UBCS team, leaving only Sgt. Nikolai Zinoviev left.[5] As day slowly broke, Dr. Mueller discovered that a group of survivors had become aware of Daylight through Dr. Jenkins' covert betrayal of Dr. Mueller,[4] and had succeeded in creating at multiple samples of Daylight. He threatened to order Thanatos to kill them, but was then shot in the head by Sgt. Zinoviev, who then activated C4 charges to destroy the building.


"Too much growth weakens an organization, What should be important becomes overshadowed by greed. Mass production?! Ridiculous! [...] One masterpiece is enough!"
— Greg in the opening cutscene of Decisions, Decisions.
"My apologies for this place being so... hectic. I have been monitoring your progress from here. I am grateful for your assistance. Daylight is it. The only resource against the T-virus. I cannot give it over to Umbrella. They're the ones responsible for the catastrophe which has befallen the city. In retrospect, the entire "t" project was a total disaster. Brute force should not be the only criteria for a weapon. It must also be beautiful, unique, and God-like. You will also assist me. You're going to play with my ultimate creation."
— Greg talking to the survivors in the Second Hall.
"Yoko, it's been two years... oh, but you might not know that. After all, what happened was so terrible... I think you'd want to erase it from your memory."
— Greg talking to Yoko in the Second Hall.


Dr. Mueller is playable in the game as "Greg". He is unlocked after beating "Decisions, Decisions" on VERY HARD, and purchased for the cost of 10,000 points. Alternatively, he can be unlocked by default on Resident Evil Outbreak File #2, purchased for 1,000 points and then Data Converted to Resident Evil Outbreak.[6]


"Greg" is a George-type character and, as such, possesses all of George's unique abilities, and cannot be played online with other George-type characters in the original game.

Greg has a health value of 3600-4000HP. His infection rate is 1.21% per minute. His movement speed is 19% lower than the default, while his attack is 15% below default. His starting items are different between games, it should be noted: in Outbreak, he starts with an Anti Virus (L);[7] in File #2, he starts with three Anti Viruses.[8]



  1. Resident Evil Outbreak File #2, special item: "Gold Glasses".
  2. Resident Evil Outbreak File #2, file: "Sealed Letter".
  3. 3.0 3.1 Resident Evil Outbreak (2003), scene: ""Decisions, Decisions" SCENE 01".
  4. 4.0 4.1 4.2 4.3 Resident Evil Outbreak (2003), file: "Peter's Diary".
  5. Resident Evil Outbreak (2003), scene: ""Decisions, Decisions" SCENE 02".
  6. Grand Bible, p.250.
  7. Official Guide Book, p.286.
  8. Grand Bible, p.255.