Frostguard

Frostguard is a main-hand sword with a chance on hit to slow your target. Frostguard is one of the few weapons found in both Warcraft III and WoW.

Source
Frostguard is crafted by Blacksmiths with a skill level of 300.

The Plans: Frostguard drops off Foreman Marcrid, a rare spawn in the Western Plaguelands.

Background
This wickedly curved and unnaturally sharp bladed weapon has an odd, bluish tint when held up to the light. Its surface is oddly cold to the touch, and in warm or humid climates a thin white sheen of frost builds up on its surface.

Frostguard was first discovered in Warcraft III: The Frozen Throne by Rexxar. Its previous owner was a footman who was the sole survivor of the naga attack on the human settlement.