Most of the new monsters do NOT have cards (you'll notice that they have 10 item drops which is the very maximum. A regular or rare item has eaten the card drop.) As far as I know, only Skoll, Skoll Pup, and God Poring have card graphic arts that we can potentially use.
Technically we can indeed ask many of the talented artists here to draw us the card graphic. But unique fun card effect isn't exactly easy to think of, and for now we aren't the most keen on it given our list of other stuff to do.