So there would be no confusion about the defacer's intension, the word "KISS" was also painted on the figure's torso. The 12th century marble statue, which is the only Romanesque sculpture left on the cathedral's facade, is believed to have been defaced early Monday.
The regional government's Head of Culture, Roman Rodriguez, called the incident an "atrocity" and vowed to track down whoever is responsible, reports Metro.
In order to preserve the statue's condition prior to the illegal makeover, officials say they have to use lasers to remove the markings. The process will be expensive, and when found, the vandal could face a €150,000 (about $174,000) fine.
Police are analyzing security footage around the cathedral and have asked the public for any information that could lead them to the vandal.
The cathedral is the burial site of Saint James the Great, an apostle of Jesus Christ.
In July, KISS headlined the Resurrection Festival in nearby Viveiro in Lugo. Current KISS drummer Eric Singer also wears the iconic "Catman" makeup when performing with the Rock and Roll Hall of Fame band.
Thumbnail Photos: Getty Images