General Zaroff is a sadistic, epicurean lunatic. He enjoys killing, which should be obvious from the fact that he had been a Russian general and must have been responsible for the slaughter of many thousands of men in battles. He is thoroughly selfish and lives for his own pleasure. His principal pleasure is not just in killing human beings but subjecting them to psychological torture by giving them a faint hope of escape. Without his refined manners, gourmet tastes, and luxurious home, Zaroff would come across as nothing but a monster. The author of the story had to give him the offsetting traits of culture and epicureanism in order to humanize him. No doubt Zaroff is extremely intelligent. In this respect he resembles his "guest" Sanger Rainsford. They are both intelligent, well-educated men of the world. They even seem to like each other in some strange way. This is because each man recognizes himself in the other, as if each is looking at his own reflection in a mirror. What each recognizes is the love of killing--although Rainsford has never thought of killing another human being until he met Zaroff.
Ernest Hemingway wrote about killing wild animals in his book Green Hills of Africa (1935) and notably in two short stories: "The Short Happy Life of Francis Macomber" and "The Snows of Kilimanjaro." Hemingway had a gift for making the reader identify with the killer, making the reader feel the pleasure it could be in killing an animal, especially a dangerous one. Hemingway especially loved bullfighting because there was a great deal of pain inflicted on the bulls and finally death by the sword of the matador; but at the same time there was some danger to the men who were doing the killing, as well as to the unfortunate horses of the mounted picadors.
It was Theodore Roosevelt, President of the United States from 1901 to 1909, who popularized the subject of big-game hunting. He wrote about his own adventures in Africa right around the turn of the century. At that time it was a rich man's sport, and people did not feel much pity for the animals because few of the animals were killed. Now with all the trophy animals on the endangered species list a great many people feel that killing animals for pleasure is disgusting. Therefore a contemporary reader's attitude towards General Zaroff would be different from when the story was published in 1924.