The lurker den and lurker, as well as the base hydralisk strain, are exclusive to Kerrigan in Co-op Missions. The lurker den and lurker are unlocked when Kerrigan reaches Level 5. Ecxept the multiplayer, the lurker den morph into hydralisk den. Upgrades for the lurker become available when Kerrigan reaches Level 6.
Increases hydralisk's movement speed and attack range.