Feral Stage
From Halopedia, the Halo wiki
The Feral Stage is the first phase of a Flood outbreak [1]. In this stage, hosts are mutated into Combat Form, and, during this period of time, the Flood attacks with no strategy; becomes extremely aggressive and berserks. Once a Proto-Gravemind has consumed enough corpses and becomes a full grown Gravemind, the infection can procede into the Coordinated Stage.
