The term Aussie Big Bird is a reference to the Australian bird, the EMU. The EMU is a large flightless bird native to Australia and is the second-largest living bird by height after the ostrich. It is also the only extant member of the genus Dromaius. The EMU is an important cultural icon of Australia and is featured on the Australian coat of arms. The three letter crossword solution for Aussie Big Bird is EMU.