The Flood Halo: Encyclopedia II - The Flood Halo - Flood forms

The Flood Halo - Flood forms

The Flood Halo - Infection forms

The Infection forms (also known as "Rangers") are small, tentacled creatures which have their own defined biological framework, which are not dependent upon a host. An infection form will seek out any life of capable bio-mass and calcium deposits to sustain itself, and proceed to attempt to use the creature as a host, by tapping into the spinal system, suppressing the host's consciousness, embedding itself in the thoracic cavity, and releasing spores which cause the host to mutate. (343 Guilty Spark mentions these "spores" during his own synopsis of the Flood life-cycle, which may be either another term for the Infection form, or an even more base form of the Flood.) At this point, the infected creature mutates into a possible one of four other forms. The Infection Form Flood parasites attack in a flood-like swarm that rapidly advances on host organisms, then physically attach themselves to a host as they try to burrow into its chest, once inside the organism will begin to modify the host's genetic code and take over. The Infection Form cannot attach to a host if the host is protected by a personal energy shield; contact with the shield will make them explode with a distinct "pop" sound and do minimal damage. However, if several dozen try to attack a shielded host they will gradually deplete their shields to the point that they are vulnerable. Thus, soldiers such as the human SPARTAN soldiers and the Covenant Elite are able to at least have some protection against the Flood and mount a counter attack, but unshielded troops (the majority of both armies) such as UNSC Marines and Covenant Grunts are quickly and easily obliterated by an attack from the Infection Form Flood.

The Flood Halo - Combat forms

If the host is strong or deemed "useful" by the parasitic infection form, then the host will be converted into a warrior or worker form, used in defensive/offensive situations as well as maintaining and repairing machinery (In Halo 2, the Flood had the ability to pilot and repair vehicles, which suggests that the flood utilize the memories and knowledge of their hosts). These warrior or combat forms are extremely strong and agile, with the Covenant Elite-derived combat forms sometimes being able to use the covenant elite technology remaining and even the energy swords of their hosts. These forms can use all UNSC and Covenant weaponry, except the Fuel Rod Cannon. Combat Flood are also capable of unarmed combat, striking with whip-like tentacles protruding from the arms of the host.

Flood Human and Flood Elites are combat forms.

The Flood Halo - Carrier forms

The second possible form an infected host can take is that of the carrier, which presumably only happens to creatures who are physically or mentally unsuitable to be Combat forms. The Carriers grow large sacs which contain several infection forms. When a Carrier is in close proximity to any number of suitable hosts, it triggers some manner of biochemical reaction, causing the sacs to explode and spread the infection forms in order to infect more hosts. This continues the Flood life cycle. Also, as the Flood do not care for their physical forms, older and worn Combat flood can be turned into Carriers once they have outlived their usefulness.

Flood Grunts are Carrier forms.

The Flood Halo - Brain forms

Brain forms are slightly infected, but not killed, like the other forms. They are used to collect information on important things, such as codes, planets, locations and species. Captain Keyes a character in the video game Halo was infected, and turned into a Brain Form.

The Flood Halo - Command forms

The command forms, due to their limited exposure in the Halo trilogy, are not well understood. Their purpose is not exactly known. The Gravemind from Halo 2 is also believed to be a command form over the Flood on Installation 05 (Delta Halo).

Adapted from the Wikipedia article "Flood forms", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki