[Old.machine]

Reddit:

There's a malevolent alien AI on the planet that's been giving everyone their visions and talking to them, manipulating them. Basically their version of the Devil. For the humans it goes by Sol and for Mother it takes the form of her human creator Campion from back on Earth. It's very likely this AI has the power to project it's will pretty far away from the planet first connecting with the rapist guy in the helmet.

It basically tricked Mother into creating a weapon for it by impersonating Campion and downloaded instructions for the serpent thing.

There was an advanced lifeform on Keppler long ago. They created the AI and it destroyed civilization. It appears their version of necromancers were in serpent form.

After Keppler's civilization fell (the serpents destroyed their world), the humanoids who survived changed slowly devolving into different species. We've now seen both, one is more intelligent and appears more humanlike, and the other is the version that attacked the village, which they kids ended up eating.

Paul being warned away from them going to the tropical zone, and mother feeling an urge to have the baby where she did, was the work of the AI. My bet is that there's remnants of civilization in the tropical zone that would educate everyone about the AI and it did NOT want them going there.