Ship, ahoy! You're speaking of Dr. Bunger, who's traveling on the British ship Samuel Enderby
when it encounters the Pequod
of Nantucket. In his hell-bent pursuit of the sperm whale that he blames for his crippled condition, Captain Ahab besieges Dr. Bunger to disclose the damage he's seen done by the Great White Whale.
In Chapter 100 of Moby-Dick, author Herman Melville introduces Dr. Bunger with this description:
His face was an exceedingly round but sober one; he was dressed in a faded blue woolen frock or shirt, and patched trowsers; and had thus far been dividing his attention between a marlingspike he held in one hand, and a pill-box held in the other, occasionally casting a critical glance at the ivory limbs of the two crippled captains.
Dr. Bunger proceeds to feed Ahab's interest in tales related to the captain's fierce adversary, suggesting the old sailor leave well enough alone before he suffers more harm. Melville continues Bunger's address to Ahab and the Enderby's Captain Boomer:
Do you know, gentlemen, that the digestive organs of the whale are so inscrutably constructed by Divine Providence, that it is quite impossible for him to completely digest even a man's arm? And he knows it too. So that what you take for the White Whale's malice is only his awkwardness. For he never means to swallow a single limb; he only thinks to terrify by feints.
In the end, of course, Captain Ahab's craving to destroy the object of his anguish causes his own demise.