The Witcher Bestiary - Mutant
Mutant Occurrence: These creatures were created by Salamandra; they are failed experiments, botched attempts to create a perfect mutant.

Immunity: Similar to that of very dexterous and able humans.

Susceptibility: Susceptible to steel swords; the Fast Style is advised.

Tactics: Quick and agile, these creatures try to outmaneuver their enemies.

Alchemy: Pituitary glands, tendons, and beast fangs.

It seems that the proposed method of mutation leads nowhere. Fast, agile and aggressive creatures are born as a result of the transformation; however, they lack intelligence. They are closer to animals than men. Of course, that does not mean we will not find any practical use for them. On the contrary, simplified mutating procedures guarantee that we can create many Mutants, which are perfect tools for spreading chaos and terror.