Flood den

The den is an organic structure that gestates various Flood forms. Such structures are only known to have been used during a battle on a Flood-controlled Shield World in February 2531.

Gameplay
In Halo Wars, Flood dens ceaselessly produce Flood forms. Flood dens can not be destroyed, but the player can damage them enough to force them into a withered, dormant state. The effect is only temporary, and, given enough time, a den will recover and begin producing more Flood forms. However, they can be destroyed by Sentinels.

List of appearances

 * Halo Wars