Who is The Grayfoots from Midnighters #3: Blue Noon and what is their importance?

The Grayfoots refers to a group of people started by Grandpa Grayfoot and his Native American tribe. Grandpa Grayfoot's granddaughter is Constanza Grayfoot. His grandson is Ernesto Grayfoot. Grandpa can communicate with the darklings and sees the midnighters as the bad guys.