Julien Sterling is a Grim Reaper and a funeral director who works with the underworld of Britain. He frequently acts as an informant to the Phantomhive family, since Vincent Phantomhive's time
Undertaker is a lean man with long gray hair, that comprises a few braids throughout, which is worn so as to hide his eyes. His eyes reflect the typical color of Grim Reaper eyes, a bright yellow green.
Julien has extensive black fingernails and a noticeable scar across his face, neck, and left pinky finger. His robe is predominantly black; additionally, his attire includes an incredibly lengthy top hat, and a gray scarf strapped across his chest and knotted by the hips.
Before, when he did not hide his identity as a Grim Reaper, Undertaker wore square, silver-framed glasses, and a black trench coat. He did not have the scars across his neck and face, but still had his ear piercings.
Known only by his profession, Undertaker is a mysterious man whose scarred face is never fully visible beneath his long hair and crooked top hat. He tends to punctuate his words with sweeping gestures and creepy giggles, and spends a considerable deal of time inside of coffins. He takes joy in frightening others, as he intentionally acts in a disconcerting manner to provoke a reaction. Undertaker frequently refers to the deceased as his "guests," and it is his hobby to remove organs from his "guests" for research
Julien is a retired Grim Reaper, and as Grell Sutcliff and Ronald Knox claim, a "deserter." He had served as a Grim Reaper for a long time, repeatedly reaping souls in a relatively peaceful, indifferent fashion, until he grew tired with the mundane process and began to experiment and tamper with human life.
Julien was a renowned Grim Reaper, who was ranked management level, and had judged souls as famous as Marie Antoinette and Robin Hood. William T. Spears said that even crying children would have willingly given up their souls to him. He was highly respected by William, but he did not return the feelings, calling William "annoying and noisy."