Fox
Few mammals demonstrate adaptability comparable to the fox. The species thrives in arctic tundra, temperate forests, arid deserts, and metropolitan centres with equal competence. Urban foxes have mastered bin raiding, traffic awareness, and the exploitation of human feeding schedules. The fox's diet encompasses everything from berries to rabbits to discarded kebabs, demonstrating omnivorous flexibility that would impress the most eclectic human gourmand. When environments change, foxes change with them, often within a single generation.
Time
Time demonstrates a form of adaptability that transcends the biological entirely. It accommodates every possible circumstance without modification because it exists as the medium through which circumstances occur rather than as an entity subject to them. Time adapted to the Big Bang's aftermath, the formation of galaxies, the emergence of life, and the invention of wristwatches with precisely equal facility. It requires no dietary adjustments, habitat modifications, or behavioural changes because it constitutes the framework within which all adaptation takes place.