T.D.o.N.B: The factory

Obviously, it was an entrance to the underground lair. Unfortunately, it was so dark there, that I had to use some firebird to spawn and illuminate the path for me.

The path was wide at first, but then it got quite narrow. The creatures would have to squeeze through if not for the fact that it was obviously not a real, functioning entrance but just pretended to be since it was all made by the sapling.

I soon discovered a system of caverns with more of the creatures, eventually arriving inside a bigger cavern. It had green crystals on the walls, providing light. In the middle, surrounded by piles of fake bones was the boss. A massive version of the creatures I kept killing as I went deeper.