Cozbi was one of the Midianite women who committed harlotry with the Israelites during the Exodus. She was the daughter of Zur (King of Midian) and appears to have intentionally seduced the Israelites to corrupt them.
She was killed by Phinehas (son of Eleazar).
Num 25:14The name of the Israelite man who was killed, who was killed with the Midianite woman, was Zimri (son of Salu)), son of Salu (father of Zimri)), a leader of a ancestral house among the Simeonites (son of Jacob)).Num 25:15And the name of the Midianite woman who was killed was Cozbi, the daughter of Zur (King of Midian)), who was head of an ancestral house in Midian.Num 25:16And the Lord spoke to Moses, saying,Num 25:17“Harass the Midianites and strike them,Num 25:18for they have harassed you with their wiles, with the matter of Peor (father of Balaam)), and with the matter of Cozbi, the daughter of a chief of Midian, their sister, who was killed on the day of the plague on account of Peor.”