The Drunken Boar is an NPC you can meet in Chapter 2 of whose quest leads to a secret area. Like other questlines, you'll have to retrieve items, fight bosses, and listen to this character's dialogue to make progress. Following the Drunken Boar's quest to completion will lead to rare rewards, including a way to find a hidden ending to the game itself.
Before starting this quest, it is recommended that you make at least enough progress in Chapter 2 to defeat the First Prince of Flowing Sands boss. This optional foe can be faced in the Valley of Despair after you take down his father and brother at other points in the area. You should get an item called the Arhat Gold Piece for beating the First Prince, which will be important later for the Drunken Boar.
The Drunken Boar is first found in the Fright Cliff area of Chapter 2, a place you can reach by traveling to the Rockrest Flat Keeper's Shrine. From this teleportation point, go to the Yellow Wind Ridge and travel across the open desert landscape. As you can see in the above video by YouTube creator Arbuckle, you should spot a large humanoid boar NPC getting sick near a brightly lit candle on some rocks in the region.
In Black Myth: Wukong, defeat Cyan Loong on Turtle Island to collect rewards for crafting legendary weapons. Gather a third Loong Pearl.
The Boar asks you to find something to sober him up, which you can find elsewhere in the area. Return to a nearby Keeper's Shrine and head to the Windrest Bridge in the Yellow Wind Formation area to start searching. Go across the bridge, then turn left and follow the path until you see a set of stairs to your right leading up into another section of the small village.
No medicine in you can craft with the NPC Xu Dog will be able to help the Drunken Boar, but some of the treatments from this character can help you out along your journey.
Travel up the stairs and turn left again and head into the small opening on your right. Inside this space is an item you can pick up
Read more on screenrant.com