Chen Stormstout, a jovial Brewmaster of Pandaria, is the most famous of a few pandarens who ever leave their hidden island homeland of Pandaria , searching for exotic ingredients for his ever-evolving concoctions.
Chen's journeys eventually brought him to the newly christened land of Durotar, and his latest brew had a plethora of strange ingredients that he feared would be too hard to acquire. He almost lost hope for his recipe when he was met by Rexxar the travelling Beastmaster. Chen asked Rexxar to retrieve the ingredients for his brew - a barrel of Thunderwater, the egg of a thunder phoenix, and a sprig of thunderbloom.
Chen was overjoyed when Rexxar returned with the ingredients, and then mixed his special brew and offered some to Rexxar, who nearly toppled over from the shock of the volatile beverage! Rexxar asked if Chen was trying to kill him, probably in the rhetorical sense but possibly not.
Chen surmised that he would have to further examine the recipe.
Having completed one phase of his journey, Chen decided to pause his brewing and join Rexxar's adventure, so that he might better appreciate this beautiful, rugged land he had found himself in. Chen and company later befriended Jaina Proudmoore, who decided to help them out, after seeing what her father had done. They helped Rexxar defend Thrall and Durotar from Kul Tiras incursions. Jaina went on her way promising to help the group defeat her father. Chen then joined the Mok'Nathal Rexxar on a secret mission to Theramore Island.
No one knows what became of him afterwards (except maybe Rexxar), but several of his empty kegs have been found scattered throughout the Barrens.