Occamy

A beautiful, carnivorous creature native to India and the Far East, resembling a winged snake, but plumed, having two legs, and reaching up to fifteen feet in length. As occamy eggshells are formed from pure soft silver, the occamy’s reputation for aggression may be overstated, as most of its interaction with humans probably has consisted of defense of its eggs (FB). The Occamy is carnivorous and known to hunt rats, birds and even monkeys (BoP).

• Gilderoy Lockhart planned on using Occamy eggs as an ingredient in his line of shampoo as they had "lustre-giving properties." The shampoo was never made because it was too dangerous and expensive (Pm).
• He told his friend Tina that Occamies can become bigger or smaller according to the available space, a trait he called "choranaptyxic" (WFT). In 1926 New York, Newt Scamander's pet Occamy escaped from his suitcase and grew as large as the Macy's Department Store attic, but when lured with a cockroach it became small enough to fit into a teapot (WFT).
• Newt gave his No-Maj friend Jacob a box of Occamy eggshells made of silver to help pay for a start-up bakery (WFT).