Doctor Krieger is a renowned scientist and creator/controller of the Trigens in the first Far Cry. He is considered a very intelligent yet unethical scientist, devoted to strengthening mankind by any means. He controlled the trigens until Doyle took over after Jack Carver killed him.
Krieger was originally a top scientist working for the Department of Defense as a geneticist, specifically working on ways to enhance combat performance of soldiers. However he was discovered to have been conducting unsanctioned tests on humans, so he became a private business owner. Presumably he used his newly gained wealth to set up a large research operation on the isolated archipelago in the Southern Pacific, as well as hiring and supplying the large mercenary force to protect it.
He is killed in Volcano, the final level of the game. However, just before that level, it's assumed Krieger is accidentally infected with the mutagen serum, and mutates into an almost fully-fledged Trigen. However, it's more than likely he intentionally infected himself.
Krieger has grey hair and wears a purple suit. Whilst barely appearing early on in the game, he is mentioned a lot by the mercenaries, who often call him crazy or weird. He is quite unscrupulous, as shown close to the end of the game, where he brutally kicks Carver out of a helicopter dozens of meters up in the air onto a nightmare island infested with Trigens, then tosses him a gun with only 10 bullets as a joke.
- Main article: Far Cry Ending
In the final level of Far Cry, Jack Carver enters Krieger's volcano fortress, only to be blasted by an SMG. Carver, barely alive, recovers and spews bullets at Krieger and his mercs and then demands the antidote from the dying man, but instead the plot takes a twist; Krieger isn't behind their infection. Krieger passes away, and the real enemy is revealed.
- He is voiced by Robert Burns.