Unsure what this insect is, not having seen one before. Possibly some sort of Neuropteran nymph? Sighted on a handrail in ANBG's Rainforest Gully. 4mm in length as can be gauged by the final image. Thanks to Marcus Leach for helping to find this colourful and curious insect.
Reminds me of something I came across in Tasmania which I couldn't decide whether it was an insect or something else no matter how much I inspected it. The colours I think I decided at the time seemed too artificial, but looking at this I may have been wrong.