Zaroff's personality, I believe, can best be described as calculating. Although a highly civilized man who has all the best pleasures of the world in food and drink, it took him no time to begin sizing up Rainsford as if Rainsford were a common simple animal. Zaroff would also demonstrate a sense of equity to his prey giving them good clothes, a set of rules, and the opportunity for a good night's rest before he played the most dangerous game with them.
Zaroff is a General, thus I think you could imagine the military clean cut features of a man. He is shorter than Rainsford and is Russian. A white man, he is often depicted in literature anthologies with a handlebar-type mustache. I see him smoking a long cigarette and alway appearing in beautiful fabrics and expensive clothes, except on the hunt.
Although we know little about Sanger Rainsford's physical appearance, we do know that General Zaroff
was a tall man past middle age, for his hair was a vivid white; but his thick eyebrows and pointed military mustache were as black as night...
Rainsford describes Zaroff as "singularly handsome" with a "bizarre quality" to his face. His eyes were also black, and he presented an "aristocratic" bearing with his
high cheekbones, a sharpcut nose, a spare, dark face...
When Zaroff smiled, he bore red lips and "pointed" teeth that often included a long, perfumed cigarette. We can assume that Zaroff and Rainsford were about the same size, since Zaroff provided him with clothing (" 'my clothes,' " Zaroff says) that proved to be a satisfactory fit.
(No doubt the gigantic Ivan was much larger than either of the other men; he was "the largest man" Rainsford had ever seen.)