Percy Abbott, in the '40s, sold "A Hat, A Duck, A Rabbit" ($1.00). I was 14. I mailed a dollar. I received a flat piece of cloth, white on one side and black on the other. It was actually two pieces of cloth, glued andor sewed together with wome "stiffening" in between. One side was white. It had a few "lines" drawn with paint to suggest a profile of a rabbit. The other side was black and also had a few lines to suggest a "fedora' (hat style). The whold thing folded in half, with the black side showing. It resembled a fedora hat (sort of!)
The "instructions" said to show the "hat", flip it "open" and reverse it to show the "white rabbit", then reverse it again to show the black side, which when opened, "sort of" resembled a black duck. The instructions told me to have an egg palmed, and allow the duck to lay an egg.
At 14, I really felt cheated. I tried it in one show, and threw it out. In 1945, a dollar was a dollar!