…or maybe just nature.  What the hell is this?

whaaaa?

It’s some sort of crystal? Fungus? Something.  This is the base of a tree in my back yard.  The hole is big and I’m concerned the tree is going to crash into my house.  What the hell is this thing?

UPDATE:  It’s a fungus.  It’s not solid like I thought it was.  Under direction to “poke it with a stick”, I did just that:

Alien fungus.