Wraith [Greyhawk]

Swordwraith: the spirit of a warrior slain in battle and held together by sheer will. It appears only at night or underground, looking like a soldier in ordinary arms and armor, but the flesh inside is ghostly, and in some light nothing shows but two glowing eyes.

Soul beckoner: a wraith more closely tied to its old life and so more firmly anchored to the Prime Material. It looks more like a shadow and is 90% undetectable outside bright light, but each life level it drains gives it more of its victim's features and form.

Swordwraiths keep all the tactical skill of the veterans they were, speak the common tongue, and may negotiate with anyone they respect as a military equal. They fight as normal warriors, and whatever weapon they wield deals 1d10. Each hit also drains 1 Strength, and a victim brought to 0 dies. Lost Strength comes back only with total bed rest, a point for each day spent doing nothing at all, or with wish, limited wish or equally strong magic. Only weapons of +2 or better hurt them; they shrug off sleep, charm and every other spell that targets the mind, and priests turn them as vampires.

A soul beckoner whispers to any victim within 240 feet. Hearers save vs. spell, with Wisdom bonuses, or are drawn toward it. A successful save turns the whisper into an eerie wail that demands a second save vs. spell or the hearer runs in panic for 1d4+1 rounds. Lured victims may retry the save each round with a cumulative +2 per round; the beckoner gains +4 to hit them, but a hit snaps the spell. Silence, or anyone unable to hear, blocks both whisper and wail.

It attacks with two claws for 1d6 each, and every hit drains a life level. Starting at 4 Hit Dice, it gains 1 HD, with matching hit points and THAC0, for each level stolen, so it can climb 2 HD in a single round. For turning, priests treat it by whatever Hit Dice it has at that moment.

Swordwraiths were career soldiers who knew nothing but fighting, and many refuse to accept they are dead. Inactive while the sun is up, they rest in barrows and burial mounds, where daytime intruders may catch them readying for the night. Small squads plan and launch midnight raids on nearby villages and attack travelers foolish enough to camp in their lands. They take no plunder and claim no land; they simply fight. They are common in hilly borderlands where two realms once warred, and turn up anywhere old battlefields and war graves lie.

Soul beckoners are solitary and usually lurk underground, waiting for prey to stray within range.

Swordwraiths neither eat nor produce anything, preying on travelers and settlers near their mounds. A soul beckoner is just a wraith variant whose bond with its former life runs unusually deep.