Green’s Dictionary of Slang

1. (Aus.) to urinate.

1963–74		B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 46: I’m flamin’ urgently desirous to syphon the python.
1986		C. Bowles G’DAY 5: When an Australian goes to urinate [...] he most often goes for a piss, a slash, or a leak. He hardly ever [...] syphons the python or points Percy at the porcelain.
1991		Age (Melbourne) 7 Dec. 130/5: Australia has much of which to be proud [...] drain the dragon, syphon the python, (point percy at the porcelain), having a liquid laugh down the great white telephone.
1997		Roger’s Profanisaurus in Viz 87 Dec. n.p.: siphon the python euph. Point Percy (qv) at the porcelain; have a piss.
2001		OnLine Dict. of Playground Sl. 🌐 siphon the python, syphon the python v. to urinate.
2016		N. Cummins Adventures of the Honey Badger [ebook] VITAL AUSSIE VERNACULAR Urinating: 1. To syphon the python 2. Having a snake’s hiss 3. A shot at the porcelain 4. Talking to a man about a horse.

2. (US) to masturbate.

2004

J. Ellroy ‘Hot-Prowl Rape-O’ in Destination: Morgue! (2004) 286: He’s got his hot-prowl hamster out. He’s siphoning said python in her lingerie drawer.