The Scythe of Thanatas is an major artifact item for D20/Pathfinder and similar systems. It was originally used in Stean Vitasovic's D&D3e fantasy dark ages Balkans campaign c2001-2002, and whilst the statistics provided are for that particular context it requires little elaboration for other game settings or systems. In the original campaign it was discovered in a in same chaotic caves near a keep on the borderlands of the Vrhbosna province by a sorcerer of medium ranked ability. The Scythe's frustration at the sorcerer's attempts to use the weapon without proficiency in narrow underground passageways generated some hilarity. The Scythe itself, as an artifact, became a feature of the entire campaign as its ever increasing urges for greater bloodshed became dominant.
In Pathfinder the Scythe is a two-handed melee weapon. Note however that this is specifically the 'war scythe' which historically was primarily by peasants during uprisings (e.g., , Hussites, battle of Sedgemoor, Ko?ciuszko Uprising etc) which required a modification of the blade and shaft. The painting by Mort de Bara by Jean-Joseph Weerts (1883), illustrated the use of this weapon (and stands in contrast to the drawing in the Players Handbook, p100).
These weapons has the following statistics common to D&D3.x/D20/Pathfinder
Scythe: 18 gp, 1d6, 2d4, ×4, 10 lb., Piercing or slashing
The Scythe of Thanatas however is encountered as the traditional peasant's tool, that is, with the chine (blade) at right angles to the snaith (haft). As a combat weapon, it is automatically at -2 due to this design, in addition to any lack of exotic weapon proficiency. To convert it to a war scythe requires a simple Craft: Weaponsmithing check with a DC of 10.
Note that the depiction of Thanatos as the "the Grim Reaper" carrying a scythe was not the norm in ancient Hellenic societies who depicted Thanatos with either a sword or an upside-down (extinguished) torch. It seems that the version most familiar in the Anglophone world actually comes from Polish origins (which, at quite a stretch, also suits the Balkans). The Hellenic Thanatos was considered more neutral in overall disposition and appeared in a male form. Note therefore that despite the Hellenic association, this is actually a Slavic artifact and could even more justifiably be called "The Scythe of Marzanna" or similar.
The Scythe has the following properties:
* Haft is manufactured from Underworld Darkwood and has a blade of Adamantine (adamastos). Note that the use of the supernatural Darkwood allows for the usually prohibited wood and admantine combination. Being made form such materials, the Scythe of Thanatos weighs only 5lbs.
* The Scythe is a Vorpal weapon; on a roll of natural 20 (followed by a successful roll to confirm the critical hit), the weapon severs the opponent's head, causing instant death. Note that the opponent must actually have a head for this to occur.
* The Scythe has a +5 Weapon Bonus enchantment.
* The Scythe is intelligent and telepathic, inhabited by a spirt named "Krv" (Blood). When it speaks to its wielder it does so in whispers and knows Koine Greek, Thracian, Serbo-Croatian, and Old Church Slavonic. Krv has a Wisdom score of 25, a Charisma score of 20, and an Intelligence of 15.
* Alignment of Neutral Evil.
* Once a day it providers the wielder, Finger of Death, Bull's Strength, Haste. Three times a day it provides Charm Person for the wielder. The wielder will also gain free use of the Sunder, Improved Initiative, Combat Reflexes, and Blind-Fight feats.
* The item has a Special Purpose to Slay All (except the wielder). It will become very annoyed if the wielder does not implement its purpose, and will engage in an Ego possession if its purpose is not carried out on at least a daily basis (although an incredibly bloody episode may lead it to be satiated for a couple of days). It will of course, first engage in encouragement first, but if the wielder resists or is incompetent, it will direct those who are unwilling, or seek one who is more skilled.
* The Scythe has Slay Living when engaging in the Special Purpose. On a successful melee touch attack to touch the subject it will kill, unless the target makes a Fortitude Save against a DC of 20. If the saving throw it successful, the target takes instead takes 3d6 + 20 points of damage.
In terms of publishing history, in addition to having an association with a certain set of caves near a well-known (if somewhat modified) Keep On The Borderlands (The Keep on the Borderlands, Gary Gygax, 1979 and Little Keep on the Borderlands, Jolly R. Blackbrun et al, 2002). the Scythe of Thanatos also has an association with the The Caverns of Thracia, Paul Jaquays, 1979. In that particular setting there is a Thracian temple to Thanatos which also includes a minor Incarnation of said deity. The Scythe will relinquish its possessive urges if it is delivered to the temple and to the incarnation, where it will be able to commune directly with a death god.