Esperanza Mozon asks a marching band to play "Happy Birthday" to the two human skulls she is carrying outside a cemetery chapel in Bolivia's capital.

Every year, hundreds of Bolivians like Mozon bring human skulls adorned with flowers to a cemetery in La Paz, asking for money, health and other favors as part of a festival.

Devotees showed up with the skulls, known as "natitas," for a short Mass on Wednesday. The ritual is celebrated a week after the Day of the Dead and includes music, dance and the lighting of candles.

The Roman Catholic Church considers the skull festival to be pagan, but it doesn't forbid people from taking part.

The festival is a mix of Andean ancestral worship and Catholic beliefs. Experts say it was common in pre-Columbian times to keep skulls as trophies and display them to symbolize death and rebirth.

Mozon named her skulls Amanda and Ron.

She got Amanda as a gift from her daughter when she was a medicine student 35 years ago. She says she found Ron in this same cemetery two decades ago.

"I think Ron was waiting for my little Amanda," Mozon said. "Every year, I do this because my 'natitas' take care of me and heal me when I'm ill."