The term 'Big Marine Mammal' can be summarized by the four-letter word 'ORCA'. Orcas, also known as killer whales, are the largest members of the dolphin family. They are found in all oceans and are highly social animals that live in pods. Orcas are apex predators, meaning they are at the top of the food chain and have no natural predators. They are known for their intelligence and playfulness, and are a popular attraction in marine parks.