I hadn't done them so far as I couldn't fit them in the expansion decks - they need to have a multiple of 18 cards per deck, so I was squeezing in as much as I could, but hadcto make some tricky decisions!
I did have fun making up a random-cards deck this time, which let me do multiples of the same cards so I now have a small pile of promo cards. I should have a go at doing something for the beasties at some point, even if I can't justify doing a full deck for them...
In the meantime, a PDF is a good idea.
I'll start thinking about rules for the other creatures and share them on here. Do feel free to make a few suggestions yourselves and I'll critique/expand on them