What is a really big carnivore that lives in the ocean that is not a shark or a whale?

Lots of carnivores live in the oceans. There are big carnivores, such as tuna, sharks, and dolphins - they eat fish mainly. There are really big carnivores, like whales, that eat anything from big animals like seals, down to tiny animals like zooplankton (little shrimps) - and there are small carnivores too, for example, salmon and squid, and some crabs and lobsters. And then there are the carnivorous plants which live in the oceans, like the bladderwort.