Psi Reaver

Psi Reavers are advanced Annelids encountered on the Von Braun and the UNN Rickenbacker in System Shock 2.

Overview
The Psi Reaver represents a final stage in the Annelid’s parasitic life cycle. When an Annelid Hybrid has mutated enough, its physical body is absorbed by the Many’s biomass. The remains from this process form a structure of nerves and bone, which resemble a brain and spinal column. These structures project powerful floating Psionic forms.

Psi Reavers are psychic beings and the most advanced and metabolically expensive forms for the Many to produce. Psi Reavers float through the air, mostly keeping their distance from the player, as the rely on ranged psychic attacks. Killing only the Psi Reaver’s floating “body” is a temporary measure - when destroyed, this projection will reappear after 30 seconds. In order to permanently kill a Psi Reaver, the player must locate and destroy its vulnerable brain stem.

Description
The Psi Reaver projection lacks any humanoid features whatsoever. They are squid-like in appearance, with four tentacle-like appendages dangling from their flesh-tone body. As psychic beings, they are capable of flotation, which is their primary means of movement. The Psi Reaver’s brain is physically separate from the “body” - the “body” is a psychic projection of the Psi Reaver’s will. The brain is defenseless and cannot move. Therefore, it's often found in alcoves or other concealed areas.

A more powerful variety, the Greater Psi Reaver, also exists.

Locations
The first Psi Reaver in System Shock 2, Anatoly Korenchkin, can be found on the Von Braun’s bridge. Several more can be found on board the Rickenbacker and inside the Many. Unlike most other enemies, Psi Reavers do not respawn or appear randomly.

Strategy
The Psi Reaver is a bit different from other enemies. Rather than attacking it directly, you should search for its brain instead, which usually will be hidden nearby. The Psi Reaver itself is big, tough and does a decent amount of damage, so it's generally not worth attacking directly. Once the brain has been destroyed, the Reaver itself can be killed for good.

How dangerous they are depends on how well they have hidden their brain structures. Psi Reaver Organs can be Researched with a small quantity of Radium for a 25% damage bonus dealt to both their projections and brain structures.