I didn't expect how this story played out, but I enjoyed it very much just the same! 
I've noticed that graphic novels tend to lack character development compared to novel-novels, but I'm gonna chalk that up to the medium itself and not take a star off for it. Gotta keep the story itself shorter for this medium.
Like I said, though, it's a fun concept and a take I didn't expect, so I'm giving M for Monster 3.5 stars! It was nothing spectacular, but it was pretty original for a kinda-sorta retelling!