
In the novel, Svengali transforms Trilby into a great singer by using hypnosis. He had one kind of cynical humour, which was more offensive than amusing, and always laughed at the wrong thing, at the wrong time, in the wrong place, and his laughter was always derisive, and full of malice. (Svengali) would either fawn or bully, and could be grossly impertinent. George Orwell wrote that Svengali, who while cleverer than the Englishmen, is evil, effeminate, and physically repugnant, was "a sinister caricature of the traditional type" and an example of "the prevailing form of antisemitism." He is continually filthy and yet still "clean enough to suit (his own) kind".

Svengali is a stereotypical antisemitic portrayal of an Ashkenazic (eastern European) Jew, complete with "bold, black, beady Jew's eyes" and a "hoarse, rasping, nasal, throaty rook's caw, his big yellow teeth baring themselves in a mongrel canine snarl".
