Graham recently made another 16-page Hidden People comic. You can order it on his website (6 dollars, and it's a limited edition).
He also put a page online:
I recently received my copy (including a personal handwritten little note and drawing by Graham himself!). It's pretty awesome, and very cheap. I let other people (people who've never heard of the Grickle comics/movies/games) read it today, and I think I created a couple of new Grickle fans in doing so. It looks just great, and it's very creepy. Buy it!
Special note for Telltale: If you're ever going to make more Grickle games and if you're ever going to put them on a dvd, and if that dvd is ever going to get a deluxe edition, a short comic like this would make it the best deluxe edition ever. Just saying.