To Build a Fire
The Man and the Wolf Dog
At first glance, you might want to think of the wolf dog as a companion for the main character; but in truth, it is more of a foil to demonstrate how the man, though tough, is not connected to his instinctive wisdom the way the animal is. In fact, the man's toughness turns out to be his downfall, because unlike the wolf dog, he does not hear instinct telling him that it's a bad idea to travel in such cold weather. The wolf dog is genetically suited to survive in much lower temperatures than the man, and yet even it knows that it shouldn't be traveling on such a cold day.