Green’s Dictionary of Slang

(Aus.) a piece of excrement.

1913		Truth (Perth) 8 Nov. 1/6: [M]any disciples of Isaac Walton, [...] aver that they have frequently spotted some nice samples of ‘blind mullet’ floating gracefully in the polluted waters of the Swan.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 19: Blind Mullet Turd.
1993		Canberra Times (ACT) 7 Jan. 6/3: As an ACT resident and ratepayer, I would like to know whether a portion of my water and sewerage rates is given to the shire council responsible for this area, to handle and clean up these schools of ‘blind mullet’.
2004		J. Lambert Macquarie Aus. Sl. Dict 18/1: blind mullet a tube of excrement floating in the water you are swimming in.
2024		J. Meades Empty Wigs (t/s) 337: Neither blind mullet was damaged.