It's not that I am afraid to die. I just don't want to be there when it happens.
- Woody Allen
The Grim Reaper is a personification of Death. These days, the Grim Reaper is usually portrayed as a skeleton or a cadaverous figure, garbed from head to foot in a black habit and hood, and carrying a large scythe. This is popular get-up for Halloween parties.
In the Middle Ages and during the intervening centuries the Grim Reaper has appeared in various guises, including as an unclothed skeleton, or even as a decomposing corpse. The Grim Reaper is sometimes shown as having wings, suggesting an angelic role (the 'Angel of Death'). In portrayals there is usually an oversized sharp instrument, either a scythe or a sickle (but sometimes an arrow or spear); there is often an hourglass or a clock; sometimes also a black crow; and occasionally a black steed as the Grim Reaper's mode of transport.
There are two main sources or traditions which The Grim Reaper seems to have derived from: the Angel of Death in the Old Testament, and the character of Kronos in Greek mythology.
The Grim Reaper as the Angel of Death
The Angel of Death figures in many different religious traditions. In Islam, for example, he is called Azrael, who is forever inscribing names in a large book, then erasing them. You are inscribed at birth and erased at death. In Judaism the generic term for the Angel of Death is Malach ha-Mavet. The Zoroastrians have Mairya, the Babylonians had Mot. And then there is the Grim Reaper.
The Angel of Death could of course be a good, holy and welcome figure, a messenger from God tasked with gathering souls for paradise; or on the other hand, as in the Passover and Exodus account of the Old Testament, tasked with slaying the Egyptians while sparing the Israelites. Over time, however, he has become confused with Satan, the fallen angels and the powers of darkness.
The Grim Reaper in Greek Mythology
Kronos (or Cronus) the Titan was given a sickle, with which he castrated his father Ouranos (Uranus). Kronos then married his sister Rhea and governed the Titans. But just as he had vanquished his father, he was afraid that his children would vanquish him, so one by one, as they were born, he swallowed them all, except for Zeus. Kronos was a god of the harvest, and the sickle with which he emasculated his father was an agricultural implement. The Roman equivalent of Kronos was Saturn, also an agricultural god. Saturn's festival was called the Saturnalia, which took place around the time we now celebrate Christmas.
Kronos seems to have become confused with Chronos, the Greek word for time. Thus the Titan Kronos with his sickle is also depicted with an hourglass, representing time. It has also been suggested that the double bulb of the hourglass represents the testes. Another association with time is that Saturn is the Bringer of Old Age.
Thus the Grim Reaper, with his sickle and hourglass, is Kronos, is Saturn, and is also Old Father Time, the harbinger of the inevitable for us mere mortals, and the harvester of souls.
When you or a loved one finally meet him face to face, rather like paying taxes or giving birth it's never going to be at a convenient time. But don't be too put out by it: remember that he is just an old man with an important job to do.
Come, lovely and soothing death,
Undulate round the world, serenely arriving, arriving,
In the day, in the night, to all, to each,
Sooner or later, delicate death.
...Praise! Praise! Praise!
For the sure-enwinding arms of cool-enfolding death...
Have none chanted for thee a chant of fullest welcome?
Then I chant it for thee, I glorify thee above all,
I bring thee a song that when thou must indeed come, come unfalteringly...
Over the tree-tops I float thee a song...
I float this carol with joy, with joy to thee, O death.
- Walt Whitman (1819 - 1892), 'Ode to Death'