Antique Iron & Copper Tool- Pattern Press? Giant Cookie Cutter?

Picked up at second hand store- Hand made tool with large handle. Very intricate design- something like a spiny crustacean or an insect, as first I thought it was a flower- until I ran a grease crayon over paper pressed against it. See the photo to see what it looks like- Handle is 6"L, the shape is 9"L x 8"W and just over 1 1/4"D. The Handle and top part is made of IRON- (my magnet stuck strongly), the rest has no attraction and I gather is made of COPPER Ribbon, bent back and forth to create the design. There are strips cut and bent within the design to provide the details of the pattern. One can tell it has been used quite a bit, but the copper can be seen on the edges and on the ribbon. There is heavy patina throughout, especially on the handle and some other substance covering most of the copper, almost like brown paint -which could be patina under what appears to be a varnish or similar.
Anyone out there have any idea what this is? Thanks in advance for your help!!