Giant Otter (Pteronura brasiliensis)

The Giant Otters or Giant River Otters are the largest otter species in the world, standing tall at 5.5 feet, including the tail, and weighing 70 pounds. 

These social creatures live in the rivers and streams of South America. These diurnal carnivores mainly eat fish, but they also eat crabs, snakes, and small caimans. 

Additionally, the Giant Otter is the most vocal among otter species. A study discovered 22 unique vocalizations among adults and 11 in baby otters3.