Gravemind
Gravemind is a fictional alien in the Halo franchise. It is the hive of the Flood and central form. It is voiced by Dee Bradley Baker.
Fictional biography
The Gravemind encountered both Master Chief and the Arbiter. It gave them an offer to defeat the Covenant Loyalists.
Development
For it's first appearance, there was supposed to be a full level about him but was replaced with an opening cutscene.
Reception
Many people didn't like Gravemind's first design. By the remake for Halo 2, his design was heavily improved and got better reception.