Spiders in Australia are considered among the most dangerous spiders in the world.Sea creatures Watch out for Australia's many dangerous sea creatures...Each of its 10-foot-long tentacles has 500,000 needles for injecting Poison into its victims.Eastern brown snake The eastern brown snake is a long (up to 6 feet!), fast -moving snake and the second most dangerous in the world The ten most poisonous snakes in the world all live in Australia!They can live in backyards and sometimes inside homes, and deliver powerful bites that cause severe pain and hateful symptoms.The indoor taipan spider is considered the most dangerous in the world and its Toxic is50 times stronger than that of the Indian cobra.The dark-colored funnel web spider is one of the most poisoning snakes in the world.Platypus may look cute, but males have toxic spines on their back legs that they use in self-defense.