Zaroff decides that hunting regular game – jaguars, tigers, etc. – is no longer challenging because these types of game animals have no ability to think or reason. He decides that the best type of animal to hunt would be one that does have these abilities. Since Zaroff values these the abilities to think and reason he wants to find a type of game or animal that he can hunt that will be able to display these qualities. It is for this reason that he stops hunting regular animals and begins to hunt men. Zaroff conveniently lives on Ship Trap Island – a place well known for trapping lost sailors. He finds this as an opportunity to hunt the game that would challenge him most – men.
Zaroff has become a bloodthirsty madman of sorts, and as such, decides that humans truly represent "The Most Dangerous Game," hence the title. He tells Rainsford that humans can reason, plan, and scheme, unlike many wild animals, and therefore they pose a greater challenge than the species he has already hunted.
Many of his kills have been taxidermied and placed upon the walls of his palatial home, stirring conversation between he and Rainsford. As the plot unfolds, we discover that Zaroff has evolved into a monster of sorts, trapping sailors and stragglers on his private island and hunting them for sport.
The name of the new animal that General Zaroff hunts is Homo sapien. In layman's terms, General Zaroff has started hunting humans.
While talking to Rainsford, General Zaroff admits that he is bored with hunting all other types of prey. He is no longer excited by hunting things like lions, tigers, and bears (oh my).
"They were no match at all for a hunter with his wits about him, and a high-powered rifle. I was bitterly disappointed. I was lying in my tent with a splitting headache one night when a terrible thought pushed its way into my mind. Hunting was beginning to bore me!"
Basically, Zaroff feels that hunting has become too easy to be exciting. The problem, as Zaroff sees it, is that the animals operate on instinct. He believes that instinct is no match for reason, so Zaroff needs to find and hunt an animal that can reason.
"It must have courage, cunning, and, above all, it must be able to reason."
Rainsford quickly responds by saying that no animal can reason. It's then that Zaroff tells Rainsford that he now hunts humans because humans can think and reason.
"That is why I use them. It gives me pleasure. They can reason, after a fashion. So they are dangerous."
In fact, Zaroff stocks his island with human prey. He deviously captures ships in order to capture crew members. Zaroff then feeds the prisoners and exercises them. That way his prey are in peak physical condition before being hunted.