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:
Discworld (world)
Reality is spread thinly on the Disc, so events may be affected by expectations, especially those of 'intelligent' species such as humans, dwarves, etc. As such, the Discworld is not governed by real-world physics or logic but by belief and narrative resolution. Essentially, if something is believed strongly enough, or by enough people, it may become true. Jokes such as treacle mines and drop bears are real on the Disc; in reality lemmings don't actually rush "en masse" off cliffs; on the Disc, they do, because that is what people believe (actually, since mass suicide would seriously foul up natural selection, they tend to abseil (or rappel) down them instead). These concepts of Discworld physics are also exploited in both wizard and witch magic. For example, when a character wishes to turn a cat into a human, the easiest way is to "convince" the cat, on a deep level, that he is a human. In fact, the main reason the Auditors of Reality dislike sentient beings in the Discworld universe is that the Auditors are the personifications of the real-world laws of physics, but the Discworld physics' power of belief and the humans' ignorance constantly remake the world, making their work fruitless.