An evil reflection is an entity which bursts out of a blood mirror and merges with a young vampire on their sixteenth birthday.
Evil reflections are non-corporeal, meaning that they do not have a physical body and cannot be seen by ordinary humans. Only the young vampire is able to see the entity. They originate from the world beyond the blood mirror.
Evil reflections can be warded off with garlic, as shown when Vlad and Robin throw garlic at Ingrid's reflection. They can influence humans to say things they otherwise wouldn't. Evil reflections seek to possess the body of a young vampire entirely, however a strong willed vampire can overcome their influence.
Notably Vladimir Dracula had not one but a thousand evil reflections.