Take a look at the guys in Braveheart too. Many of them during post battle talks look tired and dirty. They still look mostly human, but their prominent Celtic features may be the older look you want for something old and stupid. Not saying Celts are stupid, as I'm one of them. Just saying sometimes older facial features makes us think more of our clay-made neanderthal cousins more than looking at mixed race americans today who are smoother featured.
I made some heads not long ago which combined realistic "racial" features of well-known historic groups of people, with caricatured physical shapes. When you want to make realistic creatures, but want them to look different from the real-world people of the 21st century, sometimes it helps to blow those old features out of proportion, often making something we could find monstrous in the dark. Even a broken-toothed old man with a strongly bent english nose is far more frightening in the dark when you can't tell if he's smiling or grinning evilly, so use that to your advantage.
