Rocking Horse For Sale. A rocking horse is a child's toy, usually shaped like a horse and mounted on rockers similar to a rocking chair. Predecessors of the rocking horse may be seen in the rocking cradle, the tilting seats used during the Middle Ages for jousting practice as well as the wheeled hobby horse. The toy in its current form did not appear before the 17th century, though some conflicting sources note medieval manuscripts including references to carved rocking horses, presumably of the toy kind.