Scorpion's Claw

A Scorpion's Claw is one of the ritual weapons used by the Exarchs of the Striking Scorpion Warrior Aspect. Taking the form of a powered claw-shaped gauntlet, they are artfully crafted to visually resemble the mighty pincer of a real scorpion, this weapon is, in essence, the Eldar version of a Power Fist, giving the bearer vastly increased strength and armour penetration at the price of speed. A Scorpion's Claw also incorporates a Shuriken Catapult into the weapon's vambrace for ranged engagements, granting the Exarch a moderate amount of firepower while allowing him to wield another close quarter weapon in his other hand, and thus not hamper his close quarters prowess.

Sources

Codex: Eldar (6th Edition), pg. 65
Codex: Eldar (4th Edition), pp. 33, 56
Codex: Eldar (3rd Edition), pg. 35
Codex: Eldar (2nd Edition), pp. 55, 84