Flood ranged form

Background
The Flood Ranged Form is a type of Flood Pure Form 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, ceiling, or, with less frequency, on the ground. It has a mouth-like protrusion that opens up to reveal a living missile platform of regenerating spikes. These spikes will relentlessly pelt the player if exposed. They also exhibit a behavior unlike any other in the Flood arsenal. When fired upon these forms will curl up to shield their heads, their weak point. To fully disable them the player must stop firing until they reveal their weak point once more, or continue firing until they die, regardless of their defensive posture. When the Pure Form killed on a wall or ceiling, they will fall off. 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 very powerful 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 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. Note that Plasma Rifles and assault rifles are found easily therefore, one should be kept as a precaution. 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 Grenades 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 close ranged weapons like the Brute Mauler, Shotgun, Gravity Hammer, Energy Sword or a melee attack with any weapon. As true with all Flood forms the Flamethrower is an excellent weapon, as do dual-wielding Spikers and Sentinel Beam. 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 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. It should be noted that on higher difficulties, killing a Ranged Form with the Flamethrower will sometimes result in a Spike Grenade explosion. Meleeing ranged forms is an instant kill on any difficulty because they tip over.

Trivia

 * The Ranged Flood Form is universally labeled by most players (along with the Drones) as the "Most Annoying Enemy", due to their extremely high rate of fire, accuracy, and relative resistances to many weapons (such as the Assault Rifle).
 * 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, complying entirely with the last statement.
 * They are first seen on Floodgate.
 * They are almost always killed by a melee attack from any weapon, and are weak to any sparse forms of Plasma, which makes the Plasma Rifle a rather deadly weapon against it.
 * A very helpful strategy is dropping Deployable Cover because the shield cannot be weakened or penetrated by the needles they shoot. There are many deployable covers on the levels Cortana and Floodgate.
 * 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.
 * When it fires its spines, the area around it glows as though it was firing a bullet weapon.
 * To help themselves, Ranged Flood can hang upside down on ceiling and roofs, but will be on the ground.
 * They are unaffected by the Tough Luck Skull.
 * Usually, a Stalker Form will crawl onto the wall or ceiling, and then transform into a Ranged form.
 * Ranged Forms create its spikes from combat detritus.
 * If you are having trouble noticing when a Ranged Form is dead, take note in this fact: They tend to drop to one side when fatally injured.
 * Ranged Forms fire spikes that look similar to the Brute Spiker.
 * A good strategy when dealing with Ranged Forms is to continually advance towards them, dodging their projectiles, and melee them. This is quite effective since it usually takes one melee to dispose of them.
 * Ranged Forms can be killed by one melee or one grenade stick from any grenade.
 * On the level Cortana, dual-wielding Plasma Rifles are very effective due to the combined rate of fire and their weakness to Plasma.
 * They are the only Pure Form that cannot walk. Once the Stalker mutates into it, it is stuck in that spot until it dies or mutates again.