Millhouse Underground

A movie that the main characters went to see in The Last New Start chapter 21; expanded on in My Cousin's Keeper chapters 22-24. Tess casually refers to it as "the Cerberus Shark movie".

Comic Books

Noted author Maurice G Kernigan has created at least 3 separate universes in his comic books, all of which have copious amounts of fanon to support large expanded universes. The most popular two are a horror world, and a complex political thriller which is told through the eyes of a dozen highly developed spies, each of whom has adventures in different parts of the world and different strata of society. It would be possible for these stories to take place in the same universe, but it's never explicitly canon.

There is also a third series, about mafia enforcers who start dealing with supernatural threats to their city. This one is a lot darker. There is an ongoing argument (rarely civil) between fans about whether these stories are set in the same universe as either or both of Kernigan's main series; or as his 3 or 4 standalone superhero books.

About eight months before filming started on Tags, Kernigan posted on Twitter (or some equivalent site) that he was really looking forward to it, tagging the executive producer and both directors. This post was deleted after about an hour, and confused many of his fans. It was the first mention of the movie on social media; and came more than a month before it was even suspected that the producer and directors were working on a secret project together. Many of Kenigan's fans (including Ffrances Jones, who is a huge fan) then started speculating about which of Kernigan's series the movie was going to be based on.

80s movies

Some 80s movies (which were originally only available in a few countries) later came out on SVCD and laserdisc; they were mostly hated by fans because they translated events to different countries (moving the South American parts of the spy saga to China or Russia, where they inexplicably take place in the same cities as other stories but with a different mayor), or implied that some parts of the mafia books took place in Ukraine. Even fans who think the mafia and spy books are part of the same universe would have issues with the way those movies had characters from such different backgrounds happening to know each other. However, Tags included some characters who were clearly inspired by 80s movie-original characters, causing a sudden rush of people wanting to watch them now.

TV

There was previously a kids TV series, featuring a heavily modified version of the characters from the mafia comics. The show is heavily reframed, with narcissist vigilante Cerberus Shark becoming a police detective instead and taking the lead role. Many of the more sympathetic characters also lost their criminal backgrounds, and Victor Cassarone became the heir to a family pizza chain rather than a mafia family. The show is one that anyone with kids in the right age group would have heard of, but it wasn't particularly successful. It was billed as an action-adventure show, but leaned closer to comedy more often.

Movie

The movie Tags is based on Kernigan's mafia comic books, although this fact was never publicised. Before release, there were only cryptic teaser trailers, which mostly showed people running around in dark alleys, threatening each other, a man dragging an injured girl out of a collapsing building, and a burst of bright light that could possibly have been something supernatural or a spy-fi superweapon. Even many members of the cast weren't known to the public before release. This was an experimental strategy by corporate sponsor (and organiser) Claughton Innovative. It worked, generating a massive amount of buzz. People talked about the movie a lot even when they didn't know what it was.

One aspect of the trailers that a lot of people commented on was one major actor (mentioned as Jackson), who many of Kernigan's fans took to be a main character but argued about who he was supposed to be. Popular guesses were Junior (from the spy series), or Justice Goldstein (horror). He ended the second teaser trailer by slamming his fist down on a table and saying "mine!" angrily. In the end he turned out to be Cerberus Shark, although in a form that would be unrecognisable to anyone familiar with the TV series. He only showed up in the last fifteen minutes of the movie; and after it was out, many people suspected that he was setting the scene for a sequel. Even when they knew it was based on Kernigan's mafia books, most people wouldn't expect to see Cerberus Shark in it, so his sudden appearance was a big surprise to anyone who recognised his catchphrase (although his name was never mentioned in the movie, so people unfamiliar with the source material came up with a few different nicknames for him