Screamin' Banshee is character and an antagonist in Mater and the Ghostlight.
Mater and Ghostlight
"The Screamin' Banshee" lurks outside of Radiator Springs in the Ornament Valley. The Banshee waits for anyone who wanders out alone in the darkness of night. He is rarely spotted but is well known through myths and legends. Nothing can make the Banshee show fear. However, he is a bit puzzled by Mater.
He was seen at the end of Mater and the Ghostlight, with Mater in front do him. However, Mater doesn't know that it's the Screamin' Banshee and warns him of himself. Then, he drives away, drives back, says goodnight, then drives away again, leaving the Banshee puzzled.