Dr. Curtis Miller was a researcher for the WilPharma Corporation in 2005. He was fired and arrested after his aggressive disapproval of their t-Virus vaccination program. Born and raised in Harvardville, he is the older brother of Angela Miller, he lost his family in the Raccoon City Destruction Incident and made it his lifelong aim to force the United States to admit its responsibility. He was once a part of the company WilPharma, but was fired/left after a feud with the company. He eventually joined Terrasave to protest against WilPharma but Terrasave disassociated themselves due to the violent threats Curtis made to WilPharma.
He was used by the company as a scapegoat to hide the real dealers with the bioterrorists - themselves.
While he was inside the WilPharma research lab a bomb set off, destroying the building. The G-virus (most likely provided by Frederic Downing) had infected Curtis, then aided by his younger sister, Angela. He transformed in front of her and defended himself against a heavily-armed Marine task force.
He then turned on his sister to use her for breeding. Angela was saved by Leon S. Kennedy when he crushed Curtis with tons of metal schaffling. Soon enough, he began to mutate again.
Becoming even more grotesque than before, he attacked the surviving marines who were trying to escape in an elevator, tearing the elevator from its tunnel and hurtling it to the ground far below, killing all inside. He then turned to attack Leon and Angela once again.
Leon and Angela managed to avoid him for a short period of time, but he caught up with them and knocked Leon away while he chased Angela. He managed to regain consciousness for a brief moment when he picks up a picture of his family that Angela accidentally dropped from her pocket and tells her to escape.
As he lost his humanity again, he prepared to attack when suddenly the section he was standing on collapsed and he began to fall a great height. As he began to fall, he used the tail his mutation produced during his second transformation and wrapped it around Angela's foot while she was being held onto by Leon.
As Angela pleaded Leon to let her go, he refused and instead shot Curtis in his skull, causing him to release his sister and careen downwards, dying on impact along with the explosion that followed.
- He is voiced by Roger Craig Smith who is the current voice actor for Chris Redfield since Resident Evil 5.
- His first form is very similar to William Birkin's first transformation.
- His right eye, which is shadowed in his first form, is completely replaced by the eye growth on his right shoulder after his second transformation.
- The DVD features state Curtis had a son, but the picture of his family only shows he had a daughter.