The Flamingo is the animal that eats with its head upside down. Flamingos have a unique way of feeding, which involves them filtering water through their beaks to find small aquatic animals and algae. To do this, they hold their heads upside down, with their beaks pointed downward in the water. This allows them to take in water and sieve out food. It's an adaptation that has evolved to help them survive in their natural habitat.