I have not seen this padlock before. Without any name, initials, or trademark, you probably will never be able to identify the maker. I don’t think it was made by any of the major lock companies since they usually marked their products. I think we can assume it’s American from its bison motif. It probably was made during the 1880s or 1890s. I also see tracing of black japanning. Sorry I can’t be of more help. It does, however, remind me of an unmarked padlock in my collection with a horse head. It too is a wrought iron padlock, but it uses a barrel or pipe key. It does have the same shape. Could they both be from the same maker? Not sure but maybe.