I was experimenting with shader in UE4, at a certain point I kept randomly adding nodes and ended up with a creepy terrain, below

It sucks that I probably can't do this if I where to try to achieve it on purpose... ç_ç

By the way, I made a screen of the graph in case someone wants to use this material, image below

Only thing to notice is that the "flashes" happens into the fresnel so they are visible only when the player walks over the terrain, if he watches straight into it, then it is only a black goo

That's quite a neat effect.