So, in the Margreve campaign book, there IS a scenario with some ogres and bugbears and a griffon. Well, it's a talking griffon for some reason, and it was a cat or something polymorphed into a griffon? I don't know. I didn't care for the adventure too much. It wanted/forced the PCs to stealth into the (small) tower and avoid the baddies. Knowing my group, they would prefer beating the crap out of everything in the way. So, I found a tower map I really liked - LOVE EVEN - it's a badass map. I've never seen one that had all the levels crowded onto a single page. It was at the max MB limit Roll20 supports for a single image. I added in all the other stuff; the slug man, the Color Out of Space, the oozing brains and mind control. The boss monster in the original adventure was a "corrupted ogre" and it randomly gets an extra attack from an extra arm, or an extra eye, or something like that. It bored me. I wanted my monsters super effing corrupted, hence the Color Out of Space that I adapted from the 5e Mythos book. Adding in a few weird magic items and a prismatic tower burning toward the stars, and I had a pretty damn memorable arc. I also nearly killed my party., but they always seem to survive by the skin of their teeth.