Centaurs are the result of combining various kinds of animals and people and infecting them with the Forced Evolutionary Virus. These abominations are horribly disfigured creatures with little intelligence and an affinity for their super mutant masters.
Centaurs are, much like their namesake cousins from the west, the result of the Forced Evolutionary Virus being used on a combination of humans and a myriad of animals. The centaurs of the east coast stand almost as tall as an adult human. Their torsos lack arms, and their mouths are filled to the brim with writhing tentacles. Instead of legs, a centaur has multiple human arms which it uses to drag itself along the ground, which confines it to a slow, shuffling mode of travel.
Centaurs are the constant companions of super mutants, and as such can easily be an indicator of more serious threats nearby. As individuals, though, centaurs only pose a minor threat to most players. They are decently durable as opponents, and can sustain a rather large amount of damage before succumbing to their wounds, but this is offset by their weak melee attacks in the form of a lash of their tongue. They telegraph their close combat attacks quite decisively. Interestingly enough, centaurs are capable of ranged attacks as well - this in the shape of large globs of radioactive spittle. The spit itself doesn't seriously harm the player character, but it can easily lead to radiation sickness for unwary players, as they cause a staggering five rads per second for a 15 second duration. They are entirely silent creatures, lacking the ability to produce sounds of any kind, and can sneak up on an unwary player.
The basic centaur variant in Fallout 3. They are slow moving and often travel with a super mutant. Centaurs have both a long range and a close range attack. Centaurs are not a major threat, however they may cause trouble for low level players.
The following is based on Fallout 3 cut content and has not been confirmed by canon sources.
Clancy was a named centaur cut from the final release of the game. Although identical to normal centaurs stat-wise, Clancy's internal name associates him with the quest Wasteland Survival Guide. Although he cannot be found anywhere in the game, Clancy can be found in the game files. His reference id is 2d3be.