Once you’re exalted with the Tillers and best friends with every member of the Tillers Union, you can kill an Enormous Cattail Grouper for a bonus quest. Killing one in Cattail Lake will drop an Old Map which you can hand into Fish Fellreed for more info. Just what I like – another treasure hunt.
Fish suggests talking to some of the residents in Halfhill about the clues and then meeting up with her again to pinpoint the location of the treasure. It appears to be in a cave nearby.
Even with a level 90 Echoweb Toxiclaw guarding the chest, he proved no match for Cymre Jones.
The best part is you get to keep Old Man Thistle’s Treasure which contains 100G as well as one of each blue quality gem and a primal diamond. After exiting the cave (hearthing is the cheapest option as the cave is blocked soon after you enter), you take Old Man Thistle’s Almanac to Seedkeeper Shing Sing at Halfhill which earns you the achievement Ain’t Lost No More.