Flood thrasher form

The thrasher form is a variety of Flood combat form created from a creature indigenous to a Forerunner Shield World.

Summary
The thrasher form is a large Flood form that was utilized by the Flood infestation on a Shield World. Thrasher forms are not known to have been encountered elsewhere.

It takes the form of a large, hulking, tentacled creature with a slight resemblance to Earth-born primates, that attacks its opponents by ramming itself into the target and slashing with its powerful front limbs. The way the form was utilized by the Flood is similar to how the Flood tank form is employed, specifically as a powerful close-range attack unit. Despite their similarities, there are significant differences between the two forms. Unlike the tank form, the thrasher form is not a pure form, which requires that the Flood possess a fully-functioning Gravemind and a sizable reserve of biomass and calcium. The Flood on the Shield World was a Feral Stage outbreak with only a Proto-Gravemind, which, despite its size and reserves, was almost entirely built out of material and nervous systems taken from the non-sentient and semi-sentient life forms present on the artificial world.

The thrasher form is in actuality an unidentified indigenous animal that was infected and repurposed by the Flood, a process typical of a Feral Stage Flood outbreak, especially in the absence or rarity of fully sentient hosts. Other examples of infected and repurposed indigenous life forms can be seen in the bomber forms and flood swarms, which are aerial life forms infected and put to use by the Flood parasite.

List of appearances

 * Halo Wars