What's the biggest fish you've ever seen and failed to catch? I was fishing from a dock on a private lake. The lake was a clear as glass, and I saw what I thought was some mud rising from the bottom, which was out of the ordinary because the bottom of this lake was covered in vegetation, not mud. Turns out it wasn't mud, it was a mud-colored catfish that was an absolute behemoth. It was slowly coming out from under a large stand of cattails. No kid, that thing was probably 50-60 pounds. It's size was mind-boggling, around 4-5 feet in length and as fat as a sumo wrestler. I only had a popper tied on, but I cast to it nevertheless. It didn't even look at it.