The giant cuttlefish is one of the ocean’s greatest shape-shifters, able to change its colour, pattern and even the texture of its skin in the blink of an eye. Found in southern Australian waters, it uses these incredible camouflage skills to hide from predators, communicate with rivals and impress potential mates. Each winter, thousands gather in South Australia’s Upper Spencer Gulf for the world’s largest breeding aggregation of giant cuttlefish—a spectacular natural event found nowhere else on Earth. Sadly, recent harmful algal blooms have devastated this annual event, with very few cuttlefish seen aggregating near Whyalla this season (2026). Protecting healthy marine ecosystems is essential for this remarkable species, and organisations like Australian Marine Conservation Society work to safeguard Australia's oceans and marine life. During the breeding season, smaller males have even been seen disguising themselves as females to sneak past larger rivals and earn a chance to mate—a clever strategy for an animal with no bones at all.