Green’s Dictionary of Slang

1. (orig. Aus.) a mushroom.

2001		K. Sampson Outlaws (ms.) 129: Black pudding and all, three fried eggs, mushies, wads of toast.
2012		A. McKinty ‘The Dutch Book’ in Crime Factory: Hard Labour [ebook] I made her an Aussie breakfast: bacon, eggs, mushies, tomato [etc.].

2. (drugs) usu. in pl., psilocybin, ‘magic mushrooms’.

1993		I. Welsh Trainspotting 91: That’s you goat the set now. Dope, acid, speed, E, mushies, nembies, vallies, asmack, the fuckin lot.
1998		A. Warner Sopranos 294: Ah tells yous, a put a clutch of magic mushies in it.
2002		R.G. Barrett Mystery Bay Blues 263: Another chill ran up Norton’s spine and it wasn’t from the mushies.
2003		N. Griffiths Stump 146: Speed then acid then mushies then E.
2012		‘First Dog on the Moon’ in crikey,com.au 2 July 🌐 This friend of mine was on mushies and he called me on the phone and couldn’t even talk properly.