The Acid Shell is a Bio lieutenant enemy from Darkspore. They have two different stages in a combat. Their first stage is their Thorns stage, in which they will lumber towards heroes, firing projectiles. At this stage they are coated in shimmering yellow-green acid, which makes them resistant to energy-based ranged attacks, and heroes that touch them receive serious damage. Their second stage is their Shell stage, in which they will root themselves to the ground after receiving damage. In this stage their acid coating will disappear, freeing up heroes to unleash both melee and energy-based ranged attacks, although they will also have a significant resistance to damage in this state. After a few seconds they will release a burst of acidic gas that severely harms heroes in the vicinity, before unrooting themselves and resuming their Thorns stage. They are primarily found on the planet of Cryos.