Mutoids were the result of a surgical and psychological modification program carried out by the Federation. The aim was to create perfectly obediant, trustworthy followers who would never question an order or action, and who were stronger than unmodified humans. Largely this project was successful, volunteers were modified, although little information is given about the process it is known that the subjects past memories were erased, and their biochemistry radically altered. Since Mutoids were expected to be more powerful than regular humans, they had to run on a higher-octane fuel - blood serum. Human blood serum in point of fact, this led to their nickname 'vampires' amongst the rest of populace. Mutoids gain their sustinence from vials of serum which are  placed under a panel in their chests, in case of emergency they were fitted with needles to draw blood directly, this is nearly the death of Jenna in "Duel".

Mutoids really get it in the neck, they are used as cannon fodder ("The Harvest Of Kairos"), insulted and reviled ("Duel"), and largely treated like slaves. The Mutoids do not seem to mind, after all they have been conditioned to obey without question whatever the situation.
Baddies

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