Herta takes the form of a ball-jointed puppet depicting a petite young woman with long brown hair and purple eyes. She wears a frilled white, black, and purple dress which exposes her shoulders, adorned with a lock and chain pinned around her torso. She also wears a black beret decorated with a purple flower, and a purple choker with a key hanging from it. Her footwear of choice is a pair of dark purple and white boots.