Dr. Fettes is a fictional character from the novel "The Strange Case of Dr Jekyll and Mr Hyde" by Robert Louis Stevenson. He serves as a friend and confidant to Dr. Jekyll, providing insight into the duality of human nature explored in the story. In the narrative, Dr. Fettes is portrayed as a medical professional who grapples with the moral implications of scientific experimentation. His character highlights the ethical dilemmas faced by those in the medical field, particularly in relation to the darker aspects of human behavior and identity.