TARDIS Index Files

TARDIS Index Files is a YouTube series that showcases Doctor Who aliens and villains, explaining their histories and what they're capable of. They are presented by the TARDIS monitor in the Twelfth Doctor's control room, presumably making reference to the TARDIS information system and index file.

The Index Files are a monthly feature on the official Doctor Who YouTube channel, and feature illustrations from Rachael Stott.

BBC America
On 23 November 2013, the BBC America YouTube channel released a "stats" file on the Zygons for the 50th anniversary. The video was nearly identical in content to the later Who Are The Zygons, except that it took place in the Eleventh Doctor's Victorian TARDIS, and did not feature information from series 8. The BBC America version is actually much more detailed than the later Index File.