SoHP: Trapper Enemy
The trapper enemy will lie in hiding until a certain action is done, at which time it will suddenly appear and chase Hermielle relentlessly. When this happens, its better to run and navigate around obstacles than try to stand and fight. It provides us with a way to achieve an interesting change of pace in a lot of levels. In the video below you can see how relentless the swarm can be.
On the lore side, the enemy is made up of Tenebra, or black spectra. Most of the enemies in the game were constructed beings, made from black spectra for evil purposes. However, this enemy is a naturally occurring Tenebra essence, and will attack indiscriminately in its search for spectra to consume. It cannot be fought against or reasoned with, and would drain the spectra from any being in contact with it.