This article presents a typology of armed non-state actors that shape the military dimension of hybrid warfare: proxy, auxiliary, surrogate, and affiliated forces. By focusing on the kinetic domain of hybrid warfare, the article offers a corrective to a debate which has so far ignored variation in roles and functions of non-state actors and their relationships with internal and external states and their regular forces. As a denominator, 'hybrid' identifies a combination of battlespaces, types of operations -military or non-kinetic -and a blurring of actors with the scope of achieving strategic objectives by creating exploitable ambiguity. However, there has been a disproportionate focus on what hybrid war supposedly combines across battlespaces and domains (socio-political, economic, informational), at the expense of who and how this combination takes place. Using the Ukrainian crisis as a theory-building exercise, the article suggests a four-category schema that identifies non-state actor functions as a tool to better represent the complex franchise of violence that is found nested next to non-military operations in hybrid activity. In so doing, the article speaks to a call for better conceptualisation the role of non-state violent actors in civil war, in general, and in hybrid warfare, in particular.