A person dressed as Republican presidential nominee Donald Trump participates in the Greenwich Village Halloween Parade in Manhattan, New York, U.S., October 31, 2016. (Photo by Andrew Kelly/Reuters)

The tempestuous stellar nursery called the Carina Nebula, located 7,500 light-years away from Earth in the southern constellation Carina. (Photo by Reuters/NASA)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

Producer Traci Szymanski and Polish model Joanna Krupa attend the Casamigos Halloween Party at a private residence on October 28, 2016 in Beverly Hills, California. (Photo by Michael Kovac/Getty Images for Casamigos Tequila)

The 27th Annual Tompkins Square Halloween Dog Parade was held on October 21, 2017. Thousands of costumed canines and spectators marched on Tompkins Square Park to participate in the countrys largest Halloween. (Photo by Erik McGregor/Pacific Press/LightRocket via Getty Images)

Juan Carlos Vilchez, 18-months-old, dressed to represent horror movie icon Chucky, looks into a storefront mall window, in Managua, Nicaragua, Friday, October 31, 2014. Juan Carlos is wearing a first place winner that he won earlier, for best Halloween costume in his age group. (Photo by Esteban Felix/AP Photo)

A dog dressed as a Zoltar fortune telling machine participates in the Halloween Dog Parade in New York. (Photo by Timothy Clary/Getty Images)

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)