Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4239416.
Times being what the are, I wanted a more "historical" plague doctor symbol, more bat-like than bird-like wings. This is copied from a 1656 engraving of a plague doctor, the only contemporary image I could find.
Print flat with supports and make a duplicate mirrored stl file and glue together if you want a 360° symbol. It's small and fits a 3/8" or 9.5mm dowel. I had to file the end of the dowel slightly to fit. Enlarge as big as you want (or smaller if you want to make a nice lapel pin.)
The skull I happened to have from many years ago, all that remains from a skeleton model that I bought my son some 40 years ago . Thought it was a little overkill, so I put it back from whence it came. The background figure is Hieronymus Bosch's treeman from The Garden of Earthly Delights bought from a firm in the Netherlands that makes 3D art figurines from famous paintings among other things.
Just added a little stand if you don't want to bother designing one yourself.