Enforcer

Enforcers are large robotic automatons designed by the Forerunners, they are only released when situations are dire, such as the events concerning the Flood in Halo 2.

Introduction
Enforcers are massive robotic automatons that were designed to prevent mass Flood outbreaks on the Halo Rings. They are seen guarding key locations such as the entrances to the Sentinel Wall on Delta Halo and the Library. Enforcers are produced by the hovering Sentinel Production Facility.

Enforcers have two energy shields split in half with a hole int the middle(for that gun to fire) that protect the front side of the machine. They are armed with a Heavy Needler, mortar-like projectiles, and an invisible Sentinel Beam. They are also equipped with large claw like arms which are able to pick up and rip apart most vehicles, resulting in death of all occupants unfortunate enough to be inside of the vehicle.

Combat
The Enforcer's energy shields can absorb more damage than a normal Sentinel's shield. The shields, which only guard the front area of the machine, are nearly immune to ballistic weapons. They are similar to the Jackal shield, but are weak against plasma weapons. Like an Elite or Spartan, its shield can be taken out with one Plasma Pistol overload. The Enforcer is also very strong, capable of withstanding up to two Scorpion Missiles or two to three Wraith shots. Also, if a vehicle drives under an Enforcer, the Enforcer can pick up a vehicle with a gravity lift similar to that on a Phantom, then proceed to crush it with its leg-like appendages and easily destroy it, whether the vehicle is a Ghost, Warthog, Wraith, or even a Scorpion. When it appears to be lifting the player's vehicle off the ground, the driver should exit the vehicle immediately to avoid being killed. One problem with the Enforcer is that they cannot detect enemies hidden in the shadows. If a player moves stealthily enough from one area to another, the Enforcer will continue to fire into the last known area the enemy was located in. After they have lost track of their target, they will quickly lose interest and turn their back on the enemy (which gives them an opportunity to attack from behind). Once the Enforcer has taken enough damage, its shields will drop and it will explode. After exploding, large pieces will come crashing to the ground. These pieces can hurt and even kill the player if they land on them.

The Enforcer's red projectiles (similar to the Covenant Needler's) are usually not a threat to players as they are very easy to dodge. It uses these red projectiles to fight infantry at a close range. It's mortar/rocket projectiles are extremely dangerous and can quickly kill you or keep you pinned down. It will use its mortar/rocket projectiles against any vehicle it encounters; from a Ghost to a Phantom, and will occasionally use it against infantry.

If you can shoot off its small Needler shooting arms, and the small pair of energy mortars on its back, it will start to fire an invisible Sentinel Beam. Although invisible, the beam causes visible damage to walls. The sparks emitted from the weapon show that the beam is a Blue Sentinel Beam.

They were only observed on Installation 05 fighting the local Flood infestation on the levels Sacred Icon and Quarantine Zone.

Trivia

 * Enforcer's front shields form a visible and viable Marathon style logo and symbol.
 * The "crystalline guns" fire rounds somewhat similar to the Needler. It is possible that Needlers were reverse engineered from the Enforcers' weapons. Bungie did plan for another Sentinel weapon to be usable by the player referred to as the "Sentinel Needler", "Red Needler", and/or "Red Spiker". For reasons left only to Bungie, this weapon was not in the game, but the Enforcer's weapon is most likely the same gun. There was a glitch, however, that gave one Sentinel, called the Needler Sentinel, the weapon.
 * A misprint in the Official Halo 2: Strategy Guide made by Piggyback and Prima Games, mistakenly called the Enforcer a "Sentinel Major."
 * The Enforcer looks very similar to the machines seen building in the comic titled "Halo 3: The Cradle of Life".
 * Enforcers did not appear in Halo 3, possibly because an outbreak of Flood on The Ark was unexpected. However it may not have been story related and Bungie simply didn't have time, or they chose not to include them.
 * The Flood Juggernaut was stated to have been used to destroy the Enforcers that were giving the Flood such a hard time.
 * It is possible to surf these Enforcers, sort of like surfing a Sentinel. All you simply have to do is jump on top of it. Note, this is very hard to do. Also, while you are on top of an Enforcer it will not be able to attack the enemies as it will identify you as the enemy, and focus on you, making the Enforcer useless.
 * An Enforcer on the Halo 2 level Quarantine Zone can throw you into the abyss if you're on an active Spectre turret.

Related Links

 * Sentinel
 * Sentinel Major
 * Constructor
 * Sentinel Production Facility