The beast in Henry James's short novella, "The Beast in the Jungle," refers to Marcher's lifelong belief that he was destined to experience some traumatic, terrible event in his life that would overwhelm him and shake his very foundations. We see the beast clearly defined in Chapter II, when the narrator explains:
Something or other lay in wait for him, amid the twists and the turns of the months and the years, like a crouching Beast in the Jungle. (Ch. II)
The irony is that as he goes through his life waiting for this strange and terrible thing to happen to him, he lets all of life's opportunities pass him by. In fact, he meets a lovely woman named May Bartram who is even willing to become his "special friend" who stands by his side waiting with him for this fantastic event to happen. Furthermore, the narrator explains that Marcher decided never to marry because a man simply can't in good conscience take a "lady on a tiger-hunt" (Ch. II). However, his marriage to May could have indeed turned into the fantastic event that overwhelmed him by changing his life. When May is taken ill, she even begins to express doubt in his convictions and claims that the fantastic event he was waiting for has actually happened and that it was "what was to," meaning what was to have happened, what has already happened (Ch. IV).