Dark claw

The dark claw is a weapon mentioned in Tom Hall's original design document for Doom, the Doom Bible. Its description there is as follows:

Like the Unmaker, this demonic weapon never made it to the finished game. While the Unmaker was eventually realized in Doom 64, the dark claw remained abandoned. Draining life energy from enemies was a design decision that was discarded in the later stages of game development. However, the concept was used in Doom 3, in the shape of the Soul Cube. A "vampiric powerup" can also be found in the alpha versions, up until the very last versions prior to release.

Doom v0.2
An unused HUD icon graphic exists in the Doom v0.2 IWAD with the lump name, and the name of the weapon occurs in the lump.

Doom v0.3
A crude pickup sprite has been added for the weapon in Doom v0.3 as the lump, which only consists of the silhouette of the weapon taken from its HUD icon and filled in with various red gradients.

Doom v0.4
The pickup sprite has been refined into an image of a severed red hand in the Doom v0.4 IWAD. Its orientation has been reversed from the icon so that it more realistically rests on the ground.

Doom v0.5
The pickup sprite has been removed but a mysterious, empty lump still makes reference to its prior existence. The concept had apparently finally been abandoned by this point.

Other unrelated hands
A HUD overlay image from the first alpha 0.2 version contains a mention of a "Captain's Hand". Game programmer John Romero has confirmed that this item&mdash;along with the "Heart of Lothar", the other item mentioned&mdash;was only meant to be a special key, reflecting the story outlined in the Doom Bible. Starting with the v0.4 alpha, the overlay was removed. No further mentions of these items can be found.