P.12 Westland Lysander Delanne was a result of experimenting the Lysander as a turret fighter, with twin tailed Delanne tandem wing and a 4-gun Nash & Thomson power operated tail gun turret replacing the empennage (Wikipedia).
Vought V.173 Flying Pancake/ Flapjack was the brainchild of Charles Zimmerman in World War II as an experimental navy fighter. Powered by two piston engines, it was later upgraded into a larger, better version the XF5U with two radial Pratt & Whitney R-2000 engines which proved to be too heavy and below the target specifications it should achieve. The project was later cancelled and the aircraft donated to Smithsonian Institution for display.
Aerocar International’s Aerocar (Taylor Aerocar) is a series of roadable aircraftdesigns made by Moulton Taylor in 1949. It is the most successful and the most famous “flying car” design to date (Wikipedia).
The Kamov Ka-50 “Black Shark” (NATO Reporting name “Hokum”) helicopter is a single seat Russian helicopter with the distinctive coaxial rotor system employed by the Kamov design bureau. It was built in the 1980s for service with the Russian Army in 1995 (Wikipedia). The coaxial main rotor is a way of countering torque effect (if you noticed that conventional helicopters had tail rotors, those were for countering torque which tends to make the whole fuselage rotate as power is applied). In coaxial configuration, both rotors rotate in the opposite direction thus cancelling torque effect.
Sikorsky CH-54 Tarhe is a twin-engine heavylift helicopter developed by Sikorsky Aircraft for the U.S. Army (Wikipedia). The popularity of this helicopter could be recalled in the movie “Swordfish” which stars Hugh Jackman, John Travolta and Halle Berry. Remember the monster craft which had the bus tied up by a sling hooked up under her belly?
Lun Class Ekranoplan (NATO reporting name”Utka”) is a ground effect aircraft that uses extra lift of their wing when in close proximity with the surface (about 13 feet). This type of amphibious aircraft is powered by 8 Kuznetzov NK-87 turbojets mounted on front located canards and specifically tailored for maritime duties with the Russian Navy.
The Russian Mi-12 helicopter (NATO reporting name “Homer”) is the largest helicopter ever built. It made its first flight in 1967 and established world records which stand to this day. The aircraft unfortunately didn’t outlived its purpose as a rapid transporter of missiles during the cold war thus it eventually never seen production with only two prototypes built.
Du-Pont Aerospace DP-2 VTOL aircraft is an experimental aircraft testbed for an airplane that could take off like a helicopter and fly like a plane. After millions of state funds spent on the project ($63 million) and a successful hover, the program was cancelled in favour of the V-22 Osprey.
Airbus 300-600 ST (Super Transporter) is a version of a standard A300-600 widebody airliner modified to carry aircraft parts and other oversized cargo (Wikipedia). It was officially called Super Transporter but the name beluga became commonly used hence it was adopted, a shape which certainly reminds of the beluga whale.
The BN-2A Mk III Trislander or simply the Britten Norman Trislander is an 18- seat, 3- engined powered civilian utility aircraft produced in the 1970s and early 1980s by Britten-Norman of Britain (Wikipedia). The configuration of the aircraft with the 3rd engine on the tail was something unlikely hence, it was considered weird or it depends on your taste.