Unsure what this is so have placed it under 'Insects' to get the sighting into the system. It was sighted in ANBG's Rainforest Gully during rain, was around 15mm in length and relatively flat compared to its width. It moved forwards with the head end swinging from side to side, forming an S-shaped path which can be seen in several of the images. Thanks to Marcus Leach for the initial sighting.