Subjects of Equestria! We are pleased to kick off the Nightmare Night Festivities and the 14th anniversary of the return of our beloved Princess Luna! Join us in celebration!
Cannon or cannon bone: the area between the knee or hock and the fetlock joint, sometimes called the “shin” of the horse, though technically it is the third metacarpal
—Equine anatomy, Wikipedia
Okay, that’s a legitimately clever name for a pony pirate. Kudos.