Seaworld Performers include Orcas and Seals. Orcas, also known as killer whales, are the largest species of the dolphin family and are highly intelligent and social animals. Seals are semi-aquatic mammals that live in the ocean and have a streamlined body shape to help them swim quickly. Both Orcas and Seals are popular attractions at Seaworld, where they perform tricks and stunts for audiences.