Pazuzu Demon Digital Painting by TMBTM.
In ancient Mesopotamian religion, Pazuzu was the king of the demons of the wind. He also represented the southwestern wind, the bearer of storms and drought. Pazuzu was invoked in apotropaic amulets, which combat the powers of his rival, the malicious goddess Lamashtu, who was believed to cause harm to mother and child during childbirth. Although Pazuzu is, himself, considered to be an evil spirit, he drives and frightens away other evil spirits, therefore protecting humans against plagues and misfortunes.
So he was not always an evil figure as depicted in The Exorcist various series of movies.