Revellers dressed as zombies take part in an enactment of the running of the bulls a day before the start of the San Fermin festival in Pamplona, northern Spain, July 5, 2016. (Photo by Eloy Alonso/Reuters)

Attendees dressed as Poison Ivy and Harley Quinn arrive for opening day of the annual Comic-Con International in San Diego, California, United States July 21, 2016. (Photo by Mike Blake/Reuters)

A couple dressed as clowns stands near the beach during the Carnival Clown's Parade at Sesimbra village, Portugal on February 27, 2017. (Photo by Patricia De Melo Moreira/AFP Photo)

A man dressed as Darth Vader goes through the turnstile at Lermontovsky Prospekt station on the Moscow metro in Moscow, Russia on May 4, 2017. (Photo by Vyacheslav Prokofyev/TASS)

A woman dressed in a traditional Ukrainian embroidered shirt holds her cat as she take part in an embroidered shirt parade in central Kiev, Ukraine, May 27, 2017. (Photo by Gleb Garanich/Reuters)

People dressed as zombies participate in a parade for World Zombie Day 2016 in London's West End, Britain on October 9, 2016. (Photo by Splash News and Pictures)

Angel Paz, dressed as a calavera, waits with family for the start of the Gran Procession of the Catrinas, to mark the upcoming Day of the Dead holiday, in Mexico City, Sunday, October 23 2016. (Photo by Anita Baca/AP Photo)

Cosplayers dressed as She- Ra and Emma Frost pose for a photograph at the MCM Comic Con at ExCeL exhibition centre in London on October 28, 2017. (Photo by Tolga Akmen/AFP Photo)