Dornier Do 335

The Dornier Do 335 Pfeil (Arrow) is a heavy fighter built by Dornier for Germany during World War II. The Pfeil's performance was predicted to be better than other twin-engined designs due to its unusual push-pull configuration and the lower aerodynamic drag of the in-line alignment of the two engines. It is considered one of the fastest piston-engined aircraft ever and was Nazi Germany's fastest piston-engined aircraft of World War II. The Luftwaffe was desperate to get the design into operational use, but delays in engine deliveries meant that only a handful were delivered before the war ended, and it never saw combat.
The Do 335 was originally designed as a Schnellbomber. It could reach speeds around 800 km/h in level flight and could outrun most other military aircraft in service at the time, with only first-generation jet fighters being faster.