I saw one once. Maybe.
Early walleye trolling on the Ontonagon River, 20 years ago or so. A couple of young lads were fishing near the lighthouse, I trolled past a couple of times, every time one would ask if I wanted to see a 18 inch perch. Up would come the stringer. I cannot say it was 18 or not, I can say it was as big as the walleyes we had in the cooler. The fish may have been being stretched as the kid was pulling the fish up for every boat to see. I am sure at that time he was as proud of a fish as anyone.