Flood Juggernaut

Juggernaut Fight Video 76QTdEhLaBk The Flood Juggernaut is the name given to a large Flood form found encoded in the Halo 2 disc the same way as the Engineers in Halo 1. The Juggernaut Flood is very large, perhaps twice as tall as the Master Chief, coupled with the fact that it has been said that the creature's tentacles could kill the Master Chief in one blow, the name "Juggernaut" is very appropriate. It was created for Quarantine Zone as a means to stop the Sentinel Enforcers, and one can imagine with it's long legs and long tentacles, that it would have little problem snatching an Enforcer out of the sky and tearing it apart.

They were going to appear in the Arbiter levels, The Oracle and Quarantine Zone. Although the model, textures etc. are stored in the same files as High Charity, there are no Spawn Points meant for it. As such Bungie never programmed a death animation for the Juggernaut when it dies, so when killed in the game they just freeze in place.

Flood Juggernaut are Hunters?
There was a theory that the Flood Juggernaut are Flood-infected Hunters but this is actually impossible. Hunters are a mass of sentient worm-like creatures that operate under one consciousness. Due to this unique anatomy the Hunter cannot become infected. Also if you look at the middle or "The stomach" of the Juggernaut you can see what appears to be ribs (See picture). This further disproves the theory of Flood Juggernauts are Hunters, being a mass of worms Hunters don't have bones.

Heretic Experiment with Flood
Another theory has the Flood Juggernaut being created by the Heretics as an experiment gone wrong. Proponents of this theory point to how the first part of the map The Oracle is called Juggernaut as well as there being unused Spawn Points for it through out the level. However this may also be disproved because the Heretic's base, the Alpha Halo's mining facility, fell into the mass of clouds beneath it when the Arbiter cut it's cable, meaning they would have to go through alot of trouble to make it to the Quarantine Zone.