Shields units in a 6x6 area from ranged attacks. Ranged attacks with splash damage only deal minimal splash damage. Firebat and lurker attacks, and damage from cast abilities, are totally unaffected. Structures are not shielded.
Sprays all units and buildings in a 3 x 3 target area with spores that inflicts 25 damage per second for a maximum of 295 damage. 'Plague' will not kill or destroy affected units and buildings leaving at least 1 hit point. Plague does not drain shields but will affect the hit points underneath regardless of shield strength. Affected cloaked units will be revealed.
Kills a "friendly" zerg unit while giving the consuming defiler 50 energy points. The amount of energy gained is the same regardless of the unit 'consumed'. Therefore a cheap unit, such as a zergling, or one that is about to die, is considered the best "food".