Weird Fish Decoy "Thing" made of metal. Help identify?

A mystery! While this thing has the appearance and size of a fish decoy, it’s metal of some sort with a circular copper “medal” or sign on the side. A gun turrent atop! It even has fins and a lead sinker on the underside. My only guess is a carnival “float” one yanks out of the water for a prize? I’ve seen two of them over the years, this one is mine. ANY idea would be Welcome. The rust indicates long wear. Fish Decoy “form” made of metal. ???? Collection Jim Linderman / Dull Tool Dim Bulb