Worms of the Earth

Worms of the Earth are Serpent People that stopped worshipping Yig, and so were cursed by him to progressively devolve into snakes with each subsequent generation.

In the RPG...

Writing this entry is actually the first time I've read up on Worms of the Earth. I was familiar with the Serpent People, but not their degenerate kin. It seems that an encounter with them would play out differently depending on what stage of devolution the clan was at. Some are simply dwarven and less intelligent, while others appear as large snakes with rudimentary legs, and finally, others appear as regular snakes.

In a video game...

I'd be more inclined to have the Worms of the Earth as denizens in a village that can be visited and interacted with, more so than an enemy to be fought.

In a film...

The Worms of the Earth seem quite pitiful to me, so if anything, I would play up that aspect rather than have them as a source of horror. Seeing a large snake with vaguely human features would be fairly horrific, but I don't think it would be enough to prop up a film. Perhaps they could simply be included as a side-story in a Serpent Person film.