Is it a bird? Is it a plane? No..it's....
...Well frankly I'm not entirely sure. Technically it's supposed to be a unicorn, but I suspect the painter thought "sod it" I can't paint a horse's head so I'll graft a canine head [complete with a set of doggy gnashers] on to an equine body and nobody will ever notice. Nobody's ever going to see a real unicorn so anything goes. It gave this old bird a laugh though. If you double click the picture the detail should show up more clearly.
It forms part of the Charles I coat of arms in the church in Burton Park. This is the full painting in all its glory.