A B.O.W. equipped with large interchangeable arm attachments. The name Ustanak derives from the Serbian word for "rebellion." Not only is this creature powerful enough to pulverize enemies and to survive explosions without flinching, it moves uncannily fast for its gigantic size, and it relentlessly hunts Jake and Sherry. Why it is so persistent is still a mystery, although eyewitnesses have reportedly seen it in the company of a woman resembling Ada.
The Ustanak can use its arm attachments both to attack and to capture targets. Captured targets are forced into a cage it carries on its back. It has a variety of tools such as a sharp spike for skewering, and it can freely change them as required.