Notes on the Queen Leech.
Official Transcript
This creature has mutated to become the Queen Leech that controls all leeches. It typically takes the form of Dr. James Marcus, but can break this mold to become a transfigured, first form. The Queen Leech first entered the remains of Dr. Marcus many years ago and merged with his DNA.
Over a long incubation period the Queen Leech eventually began thinking and acting just like Dr. Marcus did when he was alive. As the name Queen Leech implies, it commands countless mutated leeches. If it senses bodily harm, it will cease restraining its natural functions and will mutate into a larger, second form.