The orca whales (also known as Killer Whales) are one of the biggest groups of whales living in the Kenai Fjords. They are toothed whales and are efficient predators. They have even been known to attack young Blue Whales. The only predator these predators have is the threat of humans. These whales live in life-long groups, called pods, which only contain three generations of the family. The orcas are the biggest members of the dolphin family. All in all the are the biggest dolphins. Sometimes these whales are called the "Wolves of the sea" because their behavior resembles that of the wolves.

Orca Whales can grow up to between 27 to 33 feet long, and can weigh between 8,000 and 12,000 pounds. Generally the male will be larger than the female and lead the pods to sources of food and shelter. The orcas have a diet of fish, squid, shark, and other marine animals. Orcas are born with 10 or 12 pairs of enameled teeth, which total up to around 40 or 50 of them! Every single tooth is 3 inches long! When hunting for food some pods have a tradition to cooperate together in the hunt, but there are others who just swim out for a hunt. Most orcas need to eat 551 pounds of food a day to keep up their energy! To put it simply, they need to catch about 7 or 8 seals a day and eat a bunch of fish too!

Orca whales are said to dominate the ocean. They are very intelligent and can live up to 40 years. To communicate, they use a series of high or low pitches of squeals, groans, and clicks called echolocation. One of their most prominent features is the large dorsal fin on their back. The fin on males can reach up to six feet tall! Although they are usually known for eating primarily fish, they are also known for attacking seals, porpoises, and larger whales.