First, you’ll need to find Patches the Untethered. He’s located in Murkwater Cave, a small dungeon in central Limgrave, just north of Agheel Lake. Head inside and past the Site of Grace and keep to the right, where you’ll find a small tunnel–be careful of the bandits inhabiting the cave, though. Head down the tunnel to find the yellow mist that signifies a boss fight.
Traverse the mist. Inside you’ll find a larger cave with a campfire, some boxes, and a treasure chest, but otherwise no boss. Open the chest and loot it to find some low-level cloth garments. Unfortunately these belong to Patches, and he doesn’t appreciate theft. Once the chest is open, Patches spawns on a ledge above and behind it. He quickly jumps down and attacks you.
Patches wields a spear and a shield, and can also cast the Poison Mist Incantation. Fortunately, his attacks are slow, so he’s easy to dodge. He only has about 1500 hitpoints, so most low-level players should be able to take him.
At about one-quarter health, Patches tries to surrender. You can refuse and kill him, but doing so will block off the rest of Patches’ questline. It’s a long road ahead, but it will reward you with a Magma Whip Candlestick.