blue whale

plural blue whales

1. A whale (Balaenoptera musculus), blue in color and the largest known living animal.

   1 more example

   But there are a rabble of uncertain, fugitive half-fabulous whales, which as an American whaleman, I know by reputation, but not personally....the Iceberg whale; the Quog Whale; the Blue Whale. But I omit them as altogether obsolete and can hardly help suspecting them for mere sounds full of leviathanism, but signifying nothing.

   1851, Herman Melville, Moby Dick, page 131

   Synonyms: sulfur-bottom whale, sulphur bottom whale