The
Lampyridae (Firefly) was a stealth fighter project developed by the West German manufacturer Messerschmitt-Bölkow-Blohm (MBB) in the 1980's. The program progressed as far as building and testing models and mock-ups in wind tunnels and as radar targets. The test showed that the very simple geometry resulted in a smaller radar reflelction than the American F-117
Nighthawk.
The project was cancelled in 1987.
Wikipedia has more information about the original.