Anime cartoon characters are seen on sale at the 2019 Comic Con in Warsaw, Poland on May 31, 2019. (Xinhua/Jaap Arriens)

Anime cartoon characters are seen on sale at the 2019 Comic Con in Warsaw, Poland on May 31, 2019. (Xinhua/Jaap Arriens)

An actor dressed as Spiderman is seen at the 2019 Comic Con in Warsaw, Poland on May 31, 2019. (Xinhua/Jaap Arriens)

A woman poses for photos in a replica chair known from the Game of Thrones television show at the 2019 Comic Con in Warsaw, Poland on May 31, 2019. (Xinhua/Jaap Arriens)

A woman dressed as a Japanese cartoon character gestures during a photo shooting at the 2019 Comic Con in Warsaw, Poland on May 31, 2019. (Xinhua/Jaap Arriens)

A toy merchandiser dressed as the famous Mario character is seen at the 2019 Comic Con in Warsaw, Poland on May 31, 2019. (Xinhua/Jaap Arriens)

Figures resembling the main characters from the How to Train Your Dragon movie are seen at the 2019 Comic Con in Warsaw, Poland on May 31, 2019. (Xinhua/Jaap Arriens)

Actors dressed up as Lego figures are seen at the 2019 Comic Con in Warsaw, Poland on May 31, 2019. (Xinhua/Jaap Arriens)