In 2011, Mexico City broke the world record for the largest zombie gathering in one location in the world. Guinness officially counted 9,806 participants. This official observance surpassed the previous record-holder Asbury Park, New Jersey, USA.

The interest in most zombies has come as the result of many zombie movies that were made at the end of 20th century and the start of 21st century. Some movies are: "Dawn Of The Dead" (1978), "Zombie Flesh Eaters" (1979), "The Return Of The Living Dead" (1985), "Shaun Of The Dead" (2004), "Planet Terror" (2007), "Train To Busan" (2016), etc.

Many zombie bashes are now held as annual Halloween zombie-costume parades in major cities throughout the world. A stroll with dead creatures in unbelievable 'zombie walks' is an activity that is today really exhilarating for large numbers of horror film thrill-seekers.

Even if zombies really don't exist, some people find the idea of dressing, partying, and behaving as a zombie very appealing and totally mind-boggling. These people find it very fascinating that a reanimate dead body as a mindless, clumsy corpse, which eats human flesh, will gather as part of a spontaneous flash mob and seem to work to accomplish the goal of creating more zombies.

More Info: en.wikipedia.org