The Flood Dreadnaught

This screenshot, "Dreadnaught" was created under Microsoft’s “Game Content Usage Rules” using assets from Halo 3, © Microsoft Corporation

Necros ex Machina (The Dead in the Machine), The Flood in spartan's clothing, has crashed the UNSC Olduvai onto a Forerunner shield world, which happened to be a Sanghelli colony. After wiping out the Sanghelli populus he reprogrammed the repair drones and Sentinals on the world to build him several ships similar to the Olduvai but with added Forerunner tech, The outside looked like a ship, no Flood spores seeping out or anything. The inside was completely organic, Necros ex Machina had created a new Flood Pure Form...the Flood Dreadnaught. His flagship, Diabolus, remains in orbit around the world, Nox Noctis. But the other three Dreadnoughts they sent to Earth, Sanghelios, and Bahalo. Earth's MAC guns fended off there attacker. Sanghelios' fleet annihalated the incoming Flood threat. Bahalo wasn't so lucky. The Grunt's homeworld swiftly became a Flood Hive. The portal Necros ex Machina built on the wreckage of the Olduvai allowed him to teleport to different planets to soften up their defences for next Flood assault...