The Dornier Do 335 Pfeil ("Arrow") was a heavy fighter built by Dornier for Germany during World War II. The two-seater trainer version was called Ameisenbär ("anteater"). The Pfeil's performance was predicted to be better than other twin-engine designs due to its unique push-pull configuration and the lower aerodynamic drag of the in-line alignment of the two engines. It 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.