Participants pictured dressed as zombies exit a London underground station during World Zombie Day. (Photo by Michael Mba/Demotix/Corbis)

Four men dressed as zombies participate in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

A participant dressed as a Zombie joins thousands of others as they invade the streets of London in a global event to raise money for a homeless charity. Thousands of “Zombies” invaded the streets of London in a global event to raise money for a homeless charity. (Photo by Gail-Orenstein/Demotix/Corbis)

A participant dressed as a zombie pictured during the World Zombie Day event in London. (Photo by Dave Evans/Demotix/Corbis)

Women dressed as zombies participate in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

A participant dressed as a Zombie joins thousands of others as they invade the streets of London in a global event to raise money for a homeless charity. (Photo by Gail-Orenstein/Demotix/Corbis)

Two men dressed as zombies participate in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

A man dressed as a zombie participates in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

A man dressed as a zombie participates in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

A couple dressed as zombies participates in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

A woman dressed as a zombie participates in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

A woman dressed as a zombie participates in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by SIPA Press/SEVGI)

A participant pictured dressed as a zombie during World Zombie Day in London. (Photo by Michael Mba/Demotix/Corbis)

A participant dressed as a zombie pictured during the World Zombie Day event in London. (Photo by Dave Evans/Demotix/Corbis)

A participant pictured dressed as a zombie during World Zombie Day in London. (Photo by Michael Mba/Demotix/Corbis)

Hundreds of zombies pictured participating in World Zombie Day in London. Hundreds gathered at Marble Arch to mark World Zombie Day, an annual fundraising event that grew out of Pittsburgh's first gathering at Monroeville Mall in the USA. Nowadays, the event has become quite a spectacle and is well attended. (Photo by Michael Mba/Demotix/Corbis)

A woman pictured dressed as a zombie as she roams around central London on World Zombie Day, an event that was also used to help with fundraising for the St Mungo's charity that helps homeless people in the capital. Hundreds of people dressed as zombies roamed around central London as they took part in World Zombie Day that was also held as a means of raising money for St Mungo's charity that is involved in helping homeless people in the capital. (Photo by See Li/Demotix/Corbis)