Gray Jack

Gray Jacks are decrepit Hybrids which have almost outgrown their bodies. They are not an individual strain of Chimera, since they are simply elderly Hybrids.

Description
Gray Jacks are approaching death which means that their cooling devices have become over-taxed and their high metabolic rates are cooking alive from the inside-out. This gives Gray Jacks a necrotic appearance which is followed by an odor of decaying flesh.

These Chimera are unarmed and appear to be frail, however, they possess a long reach due to their wicked claws, giving them a deadly attack. Those wounded by a strike from a Gray Jack suffer from wounds that are very difficult to clean and can eventually be fatal. Gray Jacks are never seen on the front line of combat, implying the Chimera do not regard them favorably as military units.

After the events of Resistance: Fall of Man, Gray Jacks are reported to be seen very rarely among Chimeran forces. It is believed that they are "dying" out, and have already begun to vanish from Europe as well as Menials and other older forms of Chimera. It is not clear why Hybrids no longer grow as they age in later games.

Strategy
They first appear in Cheshire - "Northern Command". They are contained in large glass specimen tanks, however they then break out of their confinement one at a time, and start attacking the player and a lone surviving soldier, if the player can save him from being strangled to death. They also appear later on in Bracknell, in the underground tunnels where they attack in small groups.
 * The best method for taking down Gray Jacks is to use the standard melee attack. This works for any weapon as the melee Gray Jacks can cause them to flinch back, allowing another melee attack. This method should enable the player to take them down without losing a single sliver of health. The best weapon to use would be the Reaper Carbine as they have two melee attacks (one per pistol), thus enabling a quicker takedown.
 * Another good tactic that has proven effective in Cheshire is to use the Fareye's secondary fire to slow down the perception of time and shoot a Gray Jack in the head as it emerges from its tank, and then repeating this strategy on the other creatures emerging from their tanks.
 * Another effective tactic is to use a Rossmore 236.
 * A more entertaining way is to lay a mine field of Sapper mines and detonate them when Gray Jacks get close to the player.
 * Using the above methods it is best to kill them as fast as possible.