Resident Evil Wiki
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 known for his rebellion against the company in 1998.


Dr. Mueller worked at the Umbrella R&D Center in Raccoon City.[1] He was already involved in the t-Virus Project by 1993, acting as the banker in an illegal human research trial conducted at a hospital in the Arklay Mountains,[2] where patients were infected with a T-Virus variant with anti-carcinogenic properties. Alongside his work with Umbrella, Mueller also worked at Raccoon University. In 1996, he used a fellow Umbrella employee, Yoko Suzuki, in t-Virus trials. He then performed an operation on her to affect her memories, which took until October 1998 to reverse.

Raccoon University, lying on top of unused facilities, became a prime space for research and storage of bioweaponry. It was here that the "Thanatos" project began development as an experimental next step following the mass production of the T-103 series. In August 1998,[3] Mueller objected to Umbrella's interest in cloning Thanatos for mass production 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 they dubbed "Daylight".[4] To cover his tracks, Mueller told Jenkins that he was a former chief researcher for Umbrella and had been smuggled a sample of the t-Virus by a colleague still in the company.[4] Rather than using it to treat the then-slowly expanding viral outbreak within the city, Mueller wanted it as leverage against Umbrella, threatening to destroy the t-Virus Project if they did not leave him and Thanatos alone.

After the modified ε strain entered Raccoon City's drinking water, tens of thousands mutated into Zombies within hours. Both Mueller and Jenkins remained in the university while their colleagues succumbed. On Thursday, October 1, Mueller executed Jenkins to tie up loose ends.[4] Aware that Umbrella would take advantage of the outbreak to send an armed team after him, Mueller decided to activate Thanatos[3] and gave it clear instructions. The B.O.W. responded by massacring a UBCS team, leaving only Sgt. Nikolai Zinoviev alive.[5] As day slowly broke, Mueller discovered that a group of survivors had become aware of Daylight through Jenkins' covert betrayal [4] and had succeeded in creating multiple samples of Daylight. He threatened to order Thanatos to kill them, but was then shot in the head by Sgt. Zinoviev, who subsequently 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 can be purchased for 10,000 points. Alternatively, he can be unlocked by default in Resident Evil Outbreak File #2, where he can be 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. He cannot be played online with other George-type characters in the original game.

Greg has a health value ranging from 3600 to 4000 HP. His infection rate is 1.21% per minute. His movement speed is 19% lower than the default, and his attack is 15% below default. It should be noted that his starting items differ between games: 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.