Pigeon
Conservative estimates place the global pigeon population at approximately 400 million individuals. Each pigeon deposits roughly 11 kilograms of waste annually, resulting in a collective output of 4.4 billion kilograms per year. This biological material has measurably altered the pH of urban surfaces worldwide and contributed to the decay of countless historical monuments.
Pigeons have served as wartime messengers, carrying vital intelligence across enemy lines. Cher Ami, a pigeon of the First World War, saved 194 American soldiers despite being shot through the breast. The species has earned 32 Dickin Medals for animal gallantry.
Thanos
The Mad Titan's influence reached its apex during the Decimation, an event that eliminated precisely 50% of all sentient life across the universe. This represents an influence score of approximately trillions of affected individuals. However, this influence proved temporary; the effects were reversed within five years.
Beyond the Snap, Thanos's influence remains largely theoretical. His philosophy of universal balance through genocide has attracted few adherents, and his home planet of Titan remains depopulated. One struggles to identify a lasting positive contribution to galactic civilisation.
VERDICT
Despite the pigeon's impressive territorial coverage, we must acknowledge that temporarily eliminating half of all life across multiple galaxies represents an influence metric the humble bird simply cannot match. Thanos takes this category, though one notes his influence was neither positive nor permanent.