Did you know? Elephant seals are the largest seals, weighing up to 8,800 pounds. [VID: Why are they called elephant seals? Elephant seals are the largest seals, weighing up to 8,800 pounds. During puberty, the nose of a male elephant seal elongates into an inflatable proboscis, which resembles an elephant’s trunk. Male elephant seals, called bulls, use their proboscis to establish their territory during the mating season. Bulls establish their territory through fighting, both physically and voca