The "Agnus Dei" is a Latin term meaning "Lamb of God." It is commonly used in Christian art to depict an image of a lamb with a halo. In many cases, the lamb holds a banner or cross to represent the sacrificial nature of Christ. The "Agnus Dei" has been portrayed in various mediums throughout history, including paintings, sculptures, and stained glass windows. This powerful and timeless symbol of faith and redemption has been a popular subject in Christian art for centuries.