Plasmic Howlers are one of the more annoying plasma minions. Their attacks inflict energy vulnerability and if that wasn't bad enough the debuff can stack leading to even more damage taken from these nasty foes.
Although they aren't very dangerous in groups. They should be dealt with caution, because the stacking debuff can be really dangerous (can stack to a maximum of 50). If you encounter howlers with other Darkspore be wary because if the other Darkspore use energy attacks your in for a world of hurt.
Plasmic Howlers can be dealt with easily with Tempest heroes, use Sage's Strangling Briars to weaken the approaching howlers and pick them off from a distance for the best results.