Doh! Amazon links not displaying the correct picture!
It's a cast iron beetle for removing wellies. The idea is you wedge the heel of one boot between the beetles "horns" and stand on its back with the other foot. You can then pull your foot out of the boot easily.
This gets used in our house several times a day. The one we have used to belong to my father and is at least 50 years old, so we have had our money's worth from it.