Christie's Out of the Ordinary auction certainly lives up to its name, following the consignment of an elaborate ornithopter flying machine.
The "Waxflatter" starred in Steven Spielberg's 1985 film Young Sherlock Holmes, and will sell with a £50,000-80,000 ($76,500-122,500) estimate in the September 5 auction in London.
The machine was made to be operational, flapping its wings through pedal power. The term ornithopter relates to any aircraft that flies by this method.
Also featuring in the auction is a giant rocking horse the size of a two-storey house, which will sell with a £25,000-40,000 ($38,256-61,209) estimate, though providing a suitable stable may be a problem for potential buyers.
The star of the sale will be a rare complete skull of a Triceratops, which was discovered at the Hell Creek Formation in Montana. It is valued at £150,000-250,000 ($230,700-384,500).
Bonhams announced recently that it will sell the famed Montana Duelling Dinosaurs on November 19 in New York, with the sale set to see a new record for any dinosaur fossil.
Paul Fraser Collectibles has already covered one of the most exciting lots of Christie's sale, Francis Bacon's paintbrushes, which are sure to attract global attention.
All of the fascinating objects on display are being made available for viewing as part of an exhibition that will open on August 5.
See some of the remarkable collectibles we have for sale in our Unique Items section.