Jason Garcia poses as The Joker from Batman at the 2015 Comic-Con International in San Diego, California, July 9, 2015. (Photo by Sandy Huffaker/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)

An attendee dressed as Junkrat from the game Overwatch poses for a picture during opening day of pop culture convention Comic Con International in San Diego, USA on Thursday, July 19, 2018. (Photo by Mike Blake/Reuters)

Attendee Emily poses for a picture at 2017 Comic-Con International on July 20, 2017 in San Diego, California. (Photo by Mike Blake/Reuters)

Rachel Hollon of Los Angeles was body painted as Harley Quinn at Comic-Con International in San Diego, USA on Jule 20, 2017. (Photo by K.C. Alfred/San Diego Union-Tribune via ZUMA Press/Rex Features/Shutterstock)

A person dressed like a zombie walks during the 2015 Comic-Con International Convention in San Diego, California July 9, 2015. The pop-culture held at the San Diego Convention Center event runs July 9-12. (Photo by Mario Anzuoni/Reuters)

Cosplayers are dressed as the Disney princesses outside Comic-Con on July 20, 2018 at the San Diego Convention Center in San Diego, California. More than 100,000 are expected at the annual comic and entertainment convention. (Photo by Mario Tama/Getty Images)