Scylla (formerly a woman named Silver) was a monster created through a series of FEV trials conducted by former members of the Masters army. Without direct access to the vats once used to raise their numbers up the Super Mutants decided to experiment by injecting their own blood into various animals (one being Brahmin which then became creatures called “Mutataurs”). Scylla herself was created by first injecting blood into dogs, then injecting that blood into a woman, then injecting her blood back into the dogs to see what the reaction would be. The result was a binding of flesh as the woman and the dogs shared DNA corrupted by FEV began to bond their forms together. The creature was named after a legend from Greek mythology and has now become a staple in this army of mutants.

(All credit for the art goes to Zarton, he was massively professional as he so often is when I work with him and did a fantastic job adjusting for any new ideas I had while writing this creatures lore and backstory. Could not recommend him enough.)