Alpha Appendage

"“A collection of alien cells begin to form at the top of your spine, coalescing into a bulbous, gelatinous mass that roils beneath your skin. Once your back can no longer contain it, the mass bursts through into the open air, revealing a viscous appendage of horrific proportions, with deep roots wrapped around your skeleton. You find that certain stressors cause a reaction in the appendage, launching a huge projectile from its open end.” —In-game description"

Effects

 * Chance to Fire Goo Bomb on Dodge
 * -40 Critical Hit