Mutant Army

Most Super Mutants in the area have one thing in common: the tops of their heads are missing, exposing a squishy green brain. This is for one of two reasons: either those captured by the Master's Army have their brains removed for consumption or mutation, or those captured by the CYBER Collective have their brains removed for personal use. 

The Master's mutants are created after a victim's brain is removed, with the empty body dipped in the FEV to rapidly mutate it. This results in rapid growth of a new brain to fill their cranial cavity within a few days at most, and the Master's telepathic influence makes it easy to impregnate their new minds with the knowledge necessary to fulfill their tasks. Mutants created by this process tend to be big and hulking, wielding military-grade heavy weapons and semi-professionally made armor, able to follow orders with ease. 

But the brain itself is not discarded. It may be consumed by the Master, who adds the organ's mass to its own and gains its knowledge in the process. It may be dipped into the FEV on its own- and after weeks of mutating and growing, mind altered by the Master's telepathic presence, becomes a Floater. It may be grafted to a wasteland beast and dipped into the vats, and the resulting Centaur used as an intelligent guard animal. 

The CYBER mutants, however, are created by injecting a brainless body with FEV. Over the course of about a week, they grow and mutate piecemeal, culminating in a