Centaur

Centaurs are misshapen, mutated creatures. They are a by-product of the Forced Evolutionary Virus, as they were created by tossing a varied mix of dogs, cats, brahmin and other animals into an FEV vat and seeing what came out the other end.

The Centaurs are not only created by the FEV, they also seem to live in a heavy radiated environment.

West Coast
On the West Coast, centaurs frequently travel in packs with floaters. They encompassed a large bulk of the Master's armies and are commonly found with the nightkin and other remnants of the Master's army who roam Northern California.

Capital Wasteland
The Centaurs encountered in the Capital Wasteland are physically different from the Centaurs from the Core Region. Mainly because it is the result of variations of FEV virus. They trade a dog like head next to the human one and feelers on the back for 3 long, tentacle like tongues. Unlike its core region 'cousins', the Capital Wasteland Centaurs use a ranged attack, a projectile that can carry lethal doses of radiation.

Although most Centaurs found in the wasteland seem to be a mixture of several animals such as Dogs and Cats, the Centaurs found around the Washington D.C. area (Fallout 3) appear to have no physical characteristics of dogs, cats or any other species other than severely deformed humans. Some even suggest that these centaurs belong to a completely different evolutionary branch than those seen in the previous Fallout games.

Centaurs are very dangerous and have long, tentacle-like tongues which can be targeted in V.A.T.S.

Appearances
Centaurs appear in Fallout, Fallout 2 and Fallout 3.It also is similer to "It" from Resident Evil 4.

Fallout and Fallout 2
Fact: Looks like the creature on the movie "Slither"