Zaroff can be described as
1. Wealthy- Rainsford's experience of receiving clothes and just looking around the room Zaroff offered him demonstrates the sheer wealth of Zaroff:
It was to a huge, beam-ceilinged bedroom with a canopied bed big enough for six men that Rainsford followed the silent giant. Ivan laid out an evening suit, and Rainsford, as he put it on, noticed that it came from a London tailor who ordinarily cut and sewed for none below the rank of duke.
2. Hospitable - Rainsford noticed that Zaroff offered him the finest foods, drinks, clothes, and had a great home in which he had invited Rainsford to stay:
He was finding the general a most thoughtful and affable host, a true cosmopolite.
3. Suspicious - Zaroff made Rainsford nervous.
But there was one small trait of the general's that made Rainsford uncomfortable. Whenever he looked up from his plate he found the general studying him, appraising him narrowly.
4. Intelligent - Zaroff admits to having read Rainsford's book, and demonstrates great craft in creating the game that he made for this island. He also says directly of himself that he has an "analytical mind":
Now, mine is an analytical mind, Mr. Rainsford. Doubtless that is why I enjoy the problems of the chase.
5. Thrill-seeking- Zaroff bored easily. He had a desire for the rush of adrenaline that can only come from the thrill of the hunt:
Hunting tigers ceased to interest me some years ago. I exhausted their possibilities, you see. No thrill left in tigers, no real danger. I live for danger, Mr. Rainsford.
Many of these quotes are captured from the same two pages in which Zaroff and Rainsford sit down to dinner for the first time.