What is a blubber fish?

There is no fish species called "blubber fish". It is likely a misunderstanding or a term that is not commonly used in scientific or everyday language.

Blubber is a thick layer of fat found in some marine mammals, such as whales, seals, and walruses, that helps them stay warm in cold water.

Perhaps you're thinking of a different type of fish? If you could provide more context or information, I might be able to help you understand what you're looking for.