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)
The plumbing of his house has greatly confused him, and in "Death's Domain" it is explained that the pipes are completely solid, as is the u-bend for the floral-decorated toilet. The towels he originally constructed are also useless; he didn't realize that they had to bend, fold and be soft. In his 'bedroom' (which he never actually sleeps in), he has a violin, which he attempts to play. As with everything in his domain, he cannot create, only mimic, so he creates a racket, instead of music. This is said to greatly frustrate him.