It took a few careful observations, close-up photos, and a bit of research before the mystery was solved. The unusual red shape, surrounded by small, unfamiliar features, turned out to be a Red Triangle Slug, scientifically known as Triboniophorus graeffei, a species commonly found along the east coast of Australia.
With its distinctive triangular marking and bold coloration, it can appear striking at first glance, sometimes leading to confusion about what it might be. However, this species is harmless and typically lives in damp, forested environments. It is often found beneath leaves, logs, or other moist surfaces, moving slowly and leaving behind a protective mucus trail that helps it navigate rough terrain.