Appearance and Personality
Buckle is a large brown stallion. When the twins needs horses to go and find the Traveling Tradesman, Conner perfers him because he is the only horse without bows in his mane. He has a saddle with large silver buckles, but is also named "Buckle" because he bucks a lot and is difficult to ride.
It is implied that he has a "complicated history" with Goldilocks' horse Porridge, and it is revealed at the end of The Enchantress Returns that Porridge is pregnant, with Buckle as a likely father. In A Grimm Warning, Porridge's foal Oats makes an appearance.
In Beyond the Kingdoms, Buckle, Porridge and Oats transport the friends to the Masked Man's cave. One look at Buckle is enough for Hagetta to cast a calming spell on him. Red Riding Hood and the Lost Boys also ride them to Morina to search for Froggy.