On the 8th day of March in the year 2013 at 2:00 PM CST
These are not official units. They are units from a fan-made customs project. And it's quite a prolific customs project, with currently over 350 units of characters from major comic book publishers! So if you want to add more superhero to your Heroscape, C3G has got you covered.
Note that the C3G units will not be shown in the lists until you explicitly choose to include them. In Battleplan, look for the option in the Catalog pane's Options box. In Treasury, click the "more" button under the "Show Placeholders" checkbox.