A Thestral is a breed of winged horses with a skeletal body, face with reptilian features, and wide, leathery wings that resemble a bat's. They are very rare, and are considered dangerous by the Ministry of Magic.
A dog collar is a piece of material put around the neck of a dog. A collar may be used for control, identification, fashion, or other purposes. Identification tags and medical information are often placed on dog collars. Collars are also useful for controlling a dog manually, as they provide a handle for grabbing.
Bungee leashes stretch. They may be made of rubber tubing or may just have an elastic section. Bungee leashes are marketed as a way to help control a dog who pulls on a leash. These leashes are designed to minimize the risk of injury to your dog's neck as he pulls. However, the best way to get your dog to not pull is to train him to walk politely on a loose leash.