When Wizards of the Coast took over TSR, there was a lot of fretting that the world’s oldest role-playing game was going to turn into D&D: The Gathering. That didn’t happen—in fact, WoTC completely reinvigorated D&D—and only one beastie in the 3.0 Monster Manual really felt like an import: the gray render. With its descriptive name, bonding habit, smashy-smashy abilities, and hulking, multi-eyed shape that looked straight out of card flavor art, you could be forgiven for wanting to tap mana every time a gray render showed up.
That doesn’t make it a bad monster though. The fact that it’s a predator who has herbivore pets is wonderfully weird. Its lack of rhyme or reason in its affections means a gray render could show up as the bodyguard of your favorite dryad or the slave of your lizardfolk archenemy. And it’s twice as deadly to structures…
Cursed with limited resources and poor soil, the thorp of Hamden is almost entirely reliant on shepherding to survive. When a gray render adopts the little hamlet’s flock as its own, the townsfolk are unable to even shear wool without arousing the creature to violence.
Driven from town after its thoughtless pranks fouled the mill (and nearly cost the miller’s daughter her life), a disconsolate faerie dragon falls in with problematic company in the deep woods. The first is a particularly large gray render that adopts the butterfly-winged dragon as its pet. The second is a redcap determined to stoke the faerie dragon’s feelings of rejections into out-and-out hate. He talks of nothing but using the great gray beast to take revenge on the townsfolk, and the faerie dragon is beginning to see things his way.
Perhaps it is the taint of iron in the river. Perhaps it is the stink of black powder. But the gunworks of Caer Iarann had only been up and running for three months when the gray renders appeared out of the forest…and began to try night after night to batter the wooden palisades of the new town down.
—Pathfinder Bestiary 2 160
Yes, of course Caer Iarann is a Princess Mononoke homage.