Sea otter in Seward, Alaska. These endangered animals are wildly adorable and very fun to watch. They are extremely social, and constantly wrestle and play with one another. It almost seems that when they aren't playing, they're either eating or sleeping. Sea otters are the largest member of the weasel family (Mustelidae) with individuals weighing between 35 and 99 pounds! Around this area, 50-70 pound sea otters are common.