Chilblains

Chilblains is a Death knight talent located in the 5th tier of the Frost Tree. Death Knights have Chains of Ice as a single-target snare and this (together with Pestilence) allows a melee range AoE snare. With the Glyph of Howling Blast this provides the Death Knight with a ranged instant cast AOE snare, something of which even frost mages can be jealous. Its usefulness in PvE is highly situational, but there are a few fights involving kiting. Highly useful in battlegrounds and arenas.