From Pluralpedia, the collaborative plurality dictionary

attacker (n.)
Applies toheadmates
CoinerPeter Parker of the Turtles All The Way Down sidesystem of The Halyconic Storms of Anemoia polymultiple astropolyplex

An attacker' is a headmate that can be similar, and, indeed, also be an Intentional Harmers. In addition to being an intentional harmer, attackers can be any other sort of a harmer, such as an Aggressor.

These headmates can attack in multiple different ways; on the inside, towards other headmates, towards people outside of the system, or to the body itself.

Attacker is designed to be a catch-all term for any headmate that causes the system harm, be it bodily, socially, emotionally, internally, or in any other way. These headmates are not considered evil, as no headmate is evil unless they declare themselves to be such, and therefore, one should not take exclusionary measures against these headmates.

Attackers, especially when they have multiple different harm-based roles, can be especially dangerous and hard to handle, be it towards the system in question or to anyone else. These headmates may or may not be able to be reasoned with about the harm in question, and they may or may not be able to undergo rehabilitation with a Rehabilitator in order to stop harming.