Orcas are a type of predatory black-and-white whales found in various Azerothian oceans, mostly around Northrend.
In the RPG
This section contains information from the Warcraft RPG which is considered non-canon.
Orca whales are whales. These ferocious creatures are also called killer whales. They are relatively small whales. They can be vicious predators, attacking virtually anything they detect. Orcas are about 30 feet long. They eat fish, squid, seals, and other whales. They can be vicious predators. Orcas are sometimes summoned by druids.