Cat
Individual cats demonstrate respectable longevity, with domestic specimens regularly achieving 15-20 years of active life. The oldest verified cat, Creme Puff of Austin, Texas, survived to 38 years, equivalent to approximately 168 human years. As a species, cats have maintained their fundamental form for roughly 12 million years.
The cat's capacity for self-preservation exceeds that of most domestic animals. Their proverbial nine lives, whilst mythological, reflect a genuine resilience that has served the species admirably throughout its cohabitation with humanity.
Monday
Monday possesses functional immortality. The concept has persisted since Babylonian astronomers established the seven-day week approximately 4,000 years ago. No individual Monday survives beyond 24 hours, yet the phenomenon regenerates with absolute certainty every 168 hours thereafter.
This cyclical immortality represents a form of temporal persistence that individual cats cannot match. Long after every currently living cat has departed, Monday will continue arriving, indifferent to extinction events, civilisational collapse, or the heat death of the universe itself.