Capybara
The capybara's physical capabilities occupy the modest end of the mammalian spectrum. Adults can achieve running speeds of approximately 35 kilometres per hour when sufficiently motivated, typically by the presence of a jaguar that has decided pursuing unbothered prey is worthwhile after all. Their incisors can process tough aquatic vegetation with reasonable efficiency.
Capybaras have been known to bite humans when provoked, though such incidents typically result in treatable wounds rather than catastrophic injury. The capybara possesses no venom, no claws of note, and no aggressive disposition. Its power lies entirely in its capacity to remain calm whilst the world around it descends into various forms of chaos. This is not power in any conventional sense, but it may be something more valuable.
Lightning
Lightning operates at scales that render comparison to mammals somewhat absurd. A single bolt can discharge one billion volts with currents reaching 200,000 amperes. The energy released—approximately one billion joules—could power a household for several weeks, yet lightning expends this quantity in less than a millisecond.
The electromagnetic forces involved generate thunder audible from 25 kilometres away, shockwaves that can damage structures, and temperatures exceeding anything found naturally on Earth's surface. Lightning kills approximately 2,000 people annually worldwide and causes billions in property damage. In any metric measuring raw physical power, lightning operates on a scale that makes biological comparisons functionally meaningless.