Numbers 25:15, 18

The name of the slain Midianite woman was Cozbi, the daughter of Zur, a tribal head of a family in Midian.

For they attacked you with the treachery that they used against you in the Peor incident. They did the same in the case involving their sister Cozbi, daughter of the Midianite leader who was killed the day the plague came at Peor.”