Model Heidi Klum attends her 8th Annual Halloween Party at The Green Door on October 31, 2007 in Los Angeles, California. (Photo by Charley Gallay/Getty Images)

A Herero man holds the head of a freshly butchered cow, killed to supply meat for a funeral, 2012. (Photo by Jim Naughten, courtesy of Klompching Gallery, New York)

Friends outside the convention center during opening day of the annual Comic-Con International in San Diego, California, United States July 21, 2016. (Photo by WENN/SIPA Press)

A Japanese girl poses in a costume at a Chara Fes (character festival) event on October 26, 2003 in Tokyo. Cosplay (costume play) is becoming popular among Japanese youths, whereby participants dress up as their favourite characters from comics, computer games and animation. (Photo by Junko Kimura/Getty Images)

Former “The Hills” star Audrina Patridge and her on again, off again boyfriend Corey Bohan get into a huge fight after attending Matthew Morrison's Halloween Party at Hyde Nightclub in West Hollywood, California on October 25, 2014. Audrina and Corey, who recently split up this past summer, seemed to be in great spirits before the party started but afterwards it was a whole different story! The not so happy couple argued on a bench and at one point a visibly upset Audrina sat on the sidewalk crying! (Photo by FameFlynet)

(L-R) Leigh-Anne Pinnock, Jesy Nelson, Perrie Edwards and Jade Thirlwall of Little Mix attend the KISS FM Haunted House Party at SSE Arena on October 29, 2015 in London, England. (Photo by Dave J. Hogan/Dave J. Hogan/Getty Images)

“Joey”, a dwarf Siamese rabbit, is dressed as Batman's sidekick Robin at a Halloween dog costume parade and contest in Long Beach, California, October 28, 2012. (Photo by Robyn Beck/AFP Pfoto)

Two years ago, Mark Rober was an engineer at NASA’s Jet Propulsion Laboratory in Pasadena, California, part of a team that worked on the Curiosity rover. For Halloween, he strapped an iPad to his chest and another to his back. Then he turned them on and used the devices’ cameras and screens to make it appear as if he had a gaping hole in the middle of his torso. (Photo By Mark Rober)