For the last few months I’ve been catching these regularly in the Tallebudgera Creek in my cast net off my jetty, I've fished there for years and have not caught them before. They puff up and when released they walk off along the bottom of four fins, not swim. They didn’t worry me before but since we are swimming a lot now with the warmer weather I’m worried about standing on them, what are they and are they venomous?
Cheers Nathan