Some animals challenge the concept of mortality, living for thousands of years. Deep-sea creatures like glass sponges, found in Antarctica's Ross Sea, can survive 10,000–15,000 years, resembling corals. Black corals in Hawaii, radiocarbon-dated to 4,265 years, grow through polyp regeneration. Ocean quahog clams, harvested in the North Atlantic, reach over 500 years, with one Icelandic specimen aged at 507. The hydra, a freshwater invertebrate, achieves immortality through endlessly renewing stem cells, though predators pose risks.

The turritopsis dohrnii, or “immortal jellyfish,” reverses its life cycle, transforming back into polyps under stress, potentially living forever. Stable aquatic environments and biological adaptations like cell regeneration enable such longevity, per Live Science. These creatures, defying time, highlight nature's remarkable ability to sustain life far beyond human lifespans, prompting awe and humility.