A mysterious kind of item Witch Doctor Mau'ari collects. But, why not collect it for the odd troll if she gives buffs for it?
Types of E'ko
[Chillwind E'ko] (
[Juju Chill], +15 Frost Resistance)
[Frostmaul E'ko] (
[Juju Might], +40 Attack Power)
[Frostsaber E'ko] (
[Juju Flurry], +3% Attack Speed)
[Ice Thistle E'ko] ( [Juju Escape], +5% Dodge)
[Shardtooth E'ko] (
[Juju Ember], +15 Fire Resistance)
[Wildkin E'ko] (
[Juju Guile], +30 Intellect)
[Winterfall E'ko] (
[Juju Power], +30 Strength)
These buffs have varying durations ranging from 10 seconds to 30 minutes. See 
[Cache of Mau'ari] for more detailed information.