Board Thread:Monster Discussions/@comment-5989773-20131230213613/@comment-16792910-20140422170302

It says Muto is presumed to be genetically engineered so either.

a.The Muto are cyborgs.

b.They are some sort of organic nano machines that can shape metals around them to a desired shape.

c.They just look metallic for no reason at all except to look cool.