Kaldorei Assassin

Kaldorei Assassins are night elves sneaking around inside and outside Kargathia Keep in Ashenvale.

Abilities

 * Deadly Poison
 * Sinister Strike
 * Sprint

Objective of

 * Drops Kaldorei Assassin's Head for the quest Security!.

Speculation
Given they wear Sentinel's Guard, they may be members of the Sentinels.