Marsh Snake - Hemiaspis signata
Mildly venomous.
General description: Fairly uniform brown, olive or black above with dark grey or black belly surface. Two prominent narrow pale-yellowish stripes on each side of face, one running from snout, through eye and onto neck area, & one below eye running from snout to corner of mouth. In juveniles the head is often darker than the body. Scales smooth.
Midbody scales at 17 rows.
Average Length: 50cm with occasional specimens nearing 70cm
http://www.wildlifeqld.com.au/Marsh_Snake.html)