The Gorefast is a strong specimen that appears as nude, hairless, skinless, missing a jaw and armed with a blade replacing it's only arm. You can easily spot one by it's red skin.
He is a little faster as well as stronger than the standard specimens, and has a fast attack, varying from slashing to spinning the blade wildly.
All the Gorefast attacks can be parried making it stumble.
If a Gorefast comes too close to the player or takes enough shots enter a sort of rage where it will Charge forward moving a lot faster as it unleashes a rather damaging combination of swings with its blade, be aware this can be parried as well making the Gorefast stumble.
An effective method in dispatching a Gorefast is to shoot it before it gets too close or to shoot it at a safe distance so it can't use it's Charging attack.