Strax Field Report

Strax Field Report was an umbrella title for a series of in-character videos that had the intention of advertising in 2013 that featured Strax sending reports back to Sontar. Later, several The Paternoster Gang Investigates short stories, published in Doctor Who Adventures in 2015 and 2016, used the format once more.

Webisodes
The original "reports" were about episodes of Doctor Who that had not yet aired and thus served as advertisements. Indeed, in at least two of the reports, the character clearly was talking about out-of-universe things, such as the name of episodes and location filming. The "field reports" were all delivered to the public on the web.

Doctor Who Adventures
In 2015, Doctor Who Adventures magazine began incorporating in-universe Strax Field Reports into their Paternoster Gang Investigates short stories. Strax relayed events he experienced by himself and with Madame Vastra and Jenny Flint in transmissions to Sontar.

Cinema introductions
In addition, cinema screenings of the television story The Day of the Doctor featured a cinema introduction by Strax, addressing the audience on the topic of cinema etiquette. In 2020, an additional prequel in the same style was webcast on Twitter by the official Doctor Who on BBC America Twitter account, written by Steven Moffat especially for the occasion, under the title of Strax Saves the Day.

The cinema screening of the series 8 premiere, Deep Breath, included a prequel to the episode featuring Strax and his fellow Paternoster Gang members Vastra and Jenny Flint, formatted similarly to a Strax Field Report, where Strax humorously recounts information about the first twelve incarnations of the Doctor to Sontar, making note of the War Doctor as well as the Tenth Doctor's aborted regeneration, before alerting them to the appearance of a new Doctor.