Sloth
Individual sloths routinely achieve lifespans of twenty to thirty years in their natural habitat, with some specimens documented surviving four decades. Their lineage, however, presents the more compelling statistic. The Folivora suborder has persisted through ice ages, continental drift, and the complete reshaping of South American ecosystems.
The giant ground sloths that once roamed the Americas measured six metres in length. Though these megafauna perished some ten thousand years ago, their arboreal descendants continue the family tradition with characteristic unhurried persistence.
Superman
Superman's personal longevity remains narratively ambiguous, with various continuities suggesting lifespans measured in centuries or potentially millennia. However, the character's cultural longevity is beyond dispute. Since his debut in Action Comics number one in 1938, the Last Son of Krypton has maintained continuous publication and cultural relevance.
Yet one must note that Superman has been killed, rebooted, and fundamentally reimagined numerous times. The sloth, by contrast, has required no editorial intervention to maintain its relevance.