For the uninitiated, Bram Stoker’s gothic horror hit Dracula is written in an epistolary format. Some of the entries throughout the story are journal notes written by Dr. John Seward, who treats inmates at an asylum. One of the inmates is a 59-year-old patient named R.M. Renfield, whose traits include “Sanguine temperament, great physical strength, morbidly excitable, periods of gloom, ending in some fixed idea which I cannot make out.”

Source: https://www.distractify.com/p/who-is-renfield-in-dracula