It was said when there was a full moon, those were the nights most feared by whites because that is when the Comanche rode on their warpaths.
The Comanche actions were the reason why Indians were pushed out of the state, save two small tribes - one in the SE corner of the state and one near El Paso.
Another thing. For some reason the Comanche liked the Germans who moved into their territory outside Austin.
In Arizona and New Mexico it was known as the APACHE MOON for the same reason.