Mmmm... Both. It was both. The centaur was made of metal and wood, and it was like it was being... puppeted from within, like a shitty mascot costume made to kill you actively. If it was it's own creature or the forest just doing it's thing, I'm not sure- I didn't get to examine it closely aside from when it was strangling me? Annnnd it's been more than a few months now.

( felicity shrugs, like they're discussing the weather. )

The forest definitely is an entity of it's own, though. While we're here, if we need anything the Shopkeeper or Trader can't get for us, we have to pay reverence to it for it to let us pass through anywhere. It controls plants, but also the fog, and has manifested as a person-like... thing made of the fog before.