Thing X was a comedy website from Adult Swim and various former staff members of The Onion that is best known as the home of On Cinema at the Cinema for its first two seasons. The site featured original videos and articles. It launched October 17, 2012.

The site was absorbed into Adult Swim's own website June 18, 2013, less than a year later. Initially, it was business as usual for the site's articles and other video content, though by 2016, On Cinema at the Cinema was all that remained from the experiment. Adult Swim would continue to carry On Cinema until 2020, when Adult Swim's digital department was gutted. HEI Network launched in its wake.