One of the most rare fancy cancels is the Waterbury (Connecticut) Running Chicken, produced by postmaster John Hill in the late 1800s. Postmasters had much more leeway in how they did things in those days and there are hundreds of stamps containing the designs of cancelling devices created from carved or whittled wood and cork.
A more common fancy is the popular Kicking Mule, known primarily from Port Townsend, Washington Territory. It sells for a fraction of the Waterbury chicken cancel, the few examples of which sell for tens of thousands of dollars when they reach the philatelic marketplace.
But one thing the philatelist knows is that there are still discoveries to be made. Is there a new, undocumented example of a variant of the Kicking Mule that has gone undiscovered, hidden in a collection or a dealer's stock for years? Stay tuned for further information.