Death (Discworld)
Death has appeared in every Discworld novel, with the exception of "The Wee Free Men" and "Snuff", and had a possible cameo at the end of "Johnny and the Dead" (the character was not identified, but spoke in unquoted small caps). The Discworld books with Death as a leading character, starting with "Mort" in 1987, are:
Death (Discworld)
""Mort"", short for Mortimer, but which also means 'death' in Quirmian (and also in French), is the title character in "Mort". He is first seen as the overly-thoughtful son of a farmer in the Octarine Grass Country, near the Ramtops. Having proved himself unworthy as a scarecrow he is chosen by Death to be his apprentice. Mort's father gave his consent, mistaking Death for an undertaker. Mort is described as being very tall and skinny, with muscles like knots in string. He has a shock of bright red hair, and walks as if he is made entirely of knees.