Not a fish, but a cetaceous mammal.
A group of whales is called a school.
The fat is called blubber.
The female is called a cow.
The fore-limbs are called paddles.
The male is called a bull-whale.
The spear used in whale-flashing is called a harpoon.
The young of whales is a cub or calf.
TOOTHED-WHALES include sperm-whales and dolphins.
WHALE-BONE WHALES include rorquals and humpbacks.
Very like a whale. Very much like a cock-and-bull story; a fudge. Hamlet chaffs Polonius by comparing a cloud to a camel, and then to a weasel, and when the courtier assents Hamlet adds, “Or like a whale”; to which Polonius answers, “Very like a whale.” (Act iii. 2.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894