Prepare to be a bit grossed out.
Dark Souls 3 boss: how to beat Rotted Greatwood
Technically, Rotted Greatwood is an optional boss; you don’t need to kill it to continue moving through the game. It does, however, hold a key item you can’t get any other way – and that in turn provides access to some of the best weapons and items out there.
If you’d rather leave it till you’re stronger, you could come back after defeating – or at least visiting – Yhorm the Giant in Profaned Capital. This arena holds a special weapon which is devastatingly effective against the Rotted Greatwood.
This boss is, uh, interesting. The battle doesn’t start till you get close, so take your time to have a look around.
You’ll notice a ton of