Flood ranged form

The Flood Ranged Form is a type of Flood from Halo 3. It is formed when a Flood Stalker Form is damaged or chooses to mount itself in a stationary position either on the walls or on the ground. It has a mouth-like protrusion that opens up to reveal a living missile platform of regenerating spikes that they relentlessly pelt the player with whenever exiting cover. They also exhibit a behavior unlike any other in the Flood arsenal, when firing upon these forms they will curl up to shield their heads, which would normally result in an instant kill. To fully disable them the player must stop firing until they reveal their weak point once more, or keep firing until they die regardless of defense. When the Pure Form is finally killed they fall off the wall they are normally attached to (it is far less common to see a Ranged Form on the ground). They can be compared directly with Carbine-carrying Sniper Jackals earlier in the game in regards to range, damage, accuracy and relative annoyance.

Killing Ranged Forms
Ranged Forms are nearly omnipresent on the battlefield and thus are extremely difficult to dispatch without first exposing yourself to fire. Your first goal should be to close the distance as normally you can only tell which direction they are firing from- they blend in quite well in the dark places they inhabit and are hard to see. When you are within sighting range, any weapon with any sort of range to it will do- the Plasma Rifle and the Brute Spiker used in short bursts (long bursts with the Plasma Rifle causes it to overheat - not good on the level "Cortana") seem to do just as well as more accurate weapons like the Carbine and the Battle Rifle, and are more common on a Flood infested battlefield so they may be your only choice. The Ranged Form is an anomaly in the mostly melee-based Flood combat and are normally hard to kill due to the simple fact that you do not normally have the ranged weapons required to take one out. In this case, well-placed Plasma Grenade and/or Spike Grenades work well, and so does a Firebomb, which requires much less accuracy as it explodes on impact next to the enemy. Ultimately, if you get within melee distance of a Ranged Form they are just as easily destroyed as any other combat form with weapons like the Brute Mauler, Shotgun, Gravity Hammer, Energy Sword or a melee attack with any other weapon. As true with all Flood the Flamethrower is an excellent weapon. The Brute Shot is a good choice for these Pure Forms as one or two grenades will, while not killing them out right (on normal, it is possible to kill a Ranged Form with 2 well placed shots), knock them off the wall they tend to be stuck to allowing you to get close enough to kill them effectively. The Brute Shot's higher than normal melee attack damage should kill them in one hit after knocking them off.

Like many Flood Forms, Ranged Forms possess a small cluster of sensory appendages emitting from their "mouths". These are located at the base of the abdomen, below the rows of projectile spines. One of the simplest ways to dispatch a Ranged Form is to target this sensory cluster while it is in a dormant state. While Ranged Forms can absorb impressive volumes of damage while dormant, a few well-placed shots to the "mouth" will kill them.

Trivia

 * The Ranged Flood Form is generally accepted by most players as the "Most Annoying Enemy", due to their high rate of fire, accuracy and relative resistance to rifles. Plasma Rifles, Needlers, Melee attacks and Grenade Sticks are generally becoming the only way to kill them on higher difficulty levels like Legendary.
 * When they transform into another Flood Form, their habit of "eating" a grenade tagged to them and making it disappear has earned them a reputation as an even cheaper and more annoying foe.
 * They are almost always killed by a melee attack from any weapon, and are weak to Plasma.
 * A very helpful strategy is droping deployable cover because the shield cannot be weakened or penetrated by the needles they shoot. There are multiple deployable covers on the level Cortana.
 * On the level Cortana, a very helpful strategy is to hide from them and pick them off the wall with the Brute Shot.
 * When attacking at medium to medium-long range, it is very effective to use the needler.
 * With the Catch Skull on, they will sometimes drop two spike grenades.
 * When it fires its spines, the area around it glows as though it was firing a bullet weapon.