At the end of Herman Melville’s great novel Moby Dick, after doing battle with Captain Ahab and drowning him, the white whale turned it malevolence on the whaling ship itself. Ramming the Pequot at high speed, the whale sent its tormentors to a watery grave with only one survivor, the story’s narrator, Ishmael.
While the tale is often thought of as an allegory, it is in fact based on two very real incidences of whales in the South Pacific sinking whaling ships, the Essex and the Ann Alexander. A survivor of the Essex sinking, Owen Chase, wrote a memoir of the ordeal that became a best seller. Melville may well have read it.
So, sperm whales ramming ships is well documented but that cannot be the primary reason for these giants of the sea to have such large and bulbous fore heads. Stuart Blackman has a fun article on sperm whales in a recent edition of Discover Wildlife.
