Combat Form

After an Infection Form has obtained a frequency match for the host's neural system, it begins to rewrite the very DNA of the body it's using. Once fully transformed, the Flood infection is in total contol of the body. Unfortunately for the host, he/she stays alive for the duration of the transformation process and is even conscious of his/her environment as the Flood take over the body. Once completely infected, the host becomes a Combat Form. Any body capable of carrying a weapon or that is still useful in combat becomes a Combat Form and is very deadly. The Combat Form grows whip-like tendrils on its arms, and will use them as melee weapons in close range.

The Flood infection is capable of not only controlling the host's body, but of also tapping into its memories to find relevant information about using weapons and equipment. In Halo 2, the Flood have learned how to tap on the host's knowledge to drive vehicles. After enough damage has been taken and the combat form cannot function effectively, it becomes a Carrier Form that incubates more Infection Forms. Eventually a Combat Form will mutate into a Carrier, regardless of damage, to perpetuate the Flood species. Some Combat Forms are equipped with energy shields or Active Camouflage.

Also in Halo 2, if the body is not destroyed, such as by an Energy Sword, grenade, or shotgun, Combat Forms can be "revived" by Infection Forms.

Note: The Combat Forms can take extensive damage before being neutralized. Arms, legs, even heads can be totally blown off of their bodies before they are incapacitated. The only known weakness of a Combat Form is its sensory feelers that normally develop in the upper chest region. This is where the Infection Form has nestled, and once destroyed, the body is incapacitated.

If you take away their arms, the body will disappear and the flood infection form comes out (Halo 2) or it's a walking potato (Halo) -- See How to make Flood Friends.

The Flood Combat Forms have also been known to completely forget about it's target and move onto another, while this can get annoying if it moves onto you, it can be quite useful to create a distraction against a large group of Covenant/Sentinals. The reason why they do this can either be a demonstration of the Flood's tatics in fighting, or just because of the game AI's intelligence.

While the ability to blow off their arms and head is common knowledge in Halo, it is not common knowledge that you can blow off the Human combat form's stomachs in Halo 1.