Blohm und Voss BV 138 Seedrache

The Blohm & Voss BV 138 Seedrache (Sea Dragon) was a three-engine seaplane. It was the Luftwaffe's main long-range maritime patrol and naval reconnaissance aircraft during World War II.

It had an unusual appearance due to its combination of unusual design features, such as its twin-boom tail unit, short hull and three-engine configuration. Source wikipedia