Gravemind

Gravemind appears in Halo 2 and seems to be a highly intelligent and extremely aware form of the Flood, possibly the collective intelligence of the Flood.(It was confirmed on the Bungie website that he is in fact a leader intelligence of the Flood.) He resembles a large venus flytrap, but can move and talk. He also apparently has the ability to tap into Delta Halo's systems, taking advantage of the teleportation grid, though apparently is unable to teleport his own Flood minions. He speaks in rhyming verse and seems to be aware of what is happening throughout the Halo. Describing Master Chief and the Arbiter, he says:

This one [Master Chief] is machine and nerve, and has its mind concluded.

This one [the Arbiter] is but flesh and faith, and is the more deluded.

He speaks mostly in trochaic heptameter, which is an example of the frequent use of the number seven in Bungie games.

Gravemind revealed to the Arbiter that the Forerunners died when the Halo fired once before. But since the Arbiter does not accept the truth, Gravemind sends the Master Chief to High Charity and the Arbiter to the Control Room of Halo Installation 05. Gravemind uses this to his advantage; in the confusion of the Covenant civil war, he spreads the Flood on High Charity where it will have the opportunity to escape from the installation.

At the end of the game, after all the credits have rolled, it is shown that Gravemind is occupying High Charity. He says to Cortana who has been separated from Master Chief and stayed behind:

Silence fills the empty grave now that I have gone,

But my mind is not at rest, for questions linger on.

Now I will ask and you will answer.

To which she answers "All right… shoot." This statement might mean that Cortana has fallen under its influence, or that she is using/learning from it, leaving the gamer not just with a cliffhanger but also with the sense that Gravemind may play a prominent role in Halo 3. When Microsoft showed the trailer for Halo 3 at E3 2006, many people claimed that Gravemind could be heard speaking with Cortana. "I have defied gods, and demons. I am your shield, I am your sword. I know you, your past, your future. This is the way the world ends." Gravemind is one of the six known Flood variants in the Halo universe.

Gravemind is voiced by Dee Bradley Baker.