Catch the World's Largest Mudfish and bring it to Old Man Barlo. You can find him fishing northeast of Shattrath City by Silmyr Lake.
Figluster's mudfish is a surprisingly quick bottom feeder found in the waters of Nagrand. They grow their entire lives and are well known as fighters.
Years ago, I caught what I'm certain was the world's biggest mudfish... until it snapped my line and escaped.
A fisherman of your caliber doesn't need to be told what to do--your destiny awaits in the lakes of Nagrand.