The crew reported that, following touchdown at Bronzewing Airport from a normal approach, they observed an unidentified object about a third of the way down the runway. As the aircraft approached the object it was identified as an emu which was close to the strip. The beta lights were confirmed and maximum reverse and braking were applied. At the same time the aircraft was moved to the right of the strip and away from the emu. The emu followed the aircraft and was struck by the left propeller as the aircraft decelerated through about 50 kts. It was thrown into the side of the fuselage. The pilot-in-command secured the left propeller and engine and the landing and taxi in were completed on one engine. The aerodrome had been inspected by a ground agent about 15 minutes prior to the aircraft’s arrival and there was no sign of the emu. The strip is surrounded by a animal-proof fence however the three gates are not self-closing. It was reported that the passenger gate had been left open overnight. It is likely the emu entered the aerodrome during the night and remained hidden until it was disturbed by the aircraft.