Don't Starve Together Guides and Walkthroughs

 

Ancient Guardian is one of the bosses you're required to defeat in order to summon the Ancient Fuelweaver. When Ancient Guardian is defeated he will drop a chest which contains many different items as well as an Ancient Key. This is one of the items needed to start the fight with the Ancient Fuelweaver boss.

You can find Ancient Guardian deep within the Ruins which are located in the caves.