A moderator on I-Nat has identified this sighting as Heteropoda jugulans. If so, according to ALA it is the southern most sighting of this species (out of over 2000 sightings)....
@KylieWaldon this is a shed moult from a huntsman, it's how they grow and get bigger. Since invertebrates don't have any bones or internal skeletons, they have to moult their exoskeleton in order to grow