The Ninth Doctor was also the first to many. He entered the rebooted world of Doctor Who decked out in a leather jacket that was just a little too big, wielding a defensive, slightly sarcastic attitude as he took Rose Tyler on a trip through time and space.

RELATED: Doctor Who: 5 Reasons Ten is the Best Doctor (& 5 It's Eleven)

He only remained part of the show for one season, but that one season was enough to reinvent Doctor Who and re-establish family drama on television. In his one season, various Easter eggs were littered around, making reference to both the past and future of the show. Did you miss these ones?

The First Bad Wolf

The concept of Bad Wolf was a chill-inducing, spine-tingling concept that we couldn’t make any sense of for the longest time. It was nothing more than two words, littered throughout time and space. The very first time those words were uttered came in the second episode of season 2, where The Moxx Of Balhoon (the fat little blue guy on a chair with angry teeth and a high pitched voice) describes something as “the Bad Wolf scenario”.

At the time, we have no idea what it is he is referring to, but by the end of the season, it’s clear that this was a little Easter egg for eagle-eyed fans.

Torchwood Relatives

Torchwood Gwen Cooper

Due to the incredible charm of Captain Jack Harkness upon his introduction in ‘The Empty Child’, he was given an adult-oriented Doctor Who spinoff named Torchwood. It left behind the child-friendly landscape and replaced it with much more adult themes. One of the central characters from the show was Gwen, played by Eve Myles.

RELATED: Doctor Who: 10 Most Shameless Things Jack Harkness Has Ever Done

The actress had previously appeared as Gwyneth in the episode ‘The Unquiet Dead’, so the two characters obviously looked very similar. Much later in the show, it is explained that the two characters are related, so this ends up being an early, unintentional Easter egg.

Bad Wolf Graffiti

Beyond that first vocal reference to Bad Wolf, it is also pretty haunting when we see it in writing. This is one of the more overt references to the concept, with a wide shot showing a child graffitiing the words onto the side of the TARDIS during the episode ‘Aliens Of London’.

Eventually, it is rubbed off, but with it being so noticeable on the screen, it really makes the audience wonder what the two seemingly unrelated words mean. By the end of the season, all of these tiny Easter eggs pay off spectacularly.

More Bad Wolf Graffiti

Doctor Who Pete Tyler dies

This is a similar idea to that above but shows the commitment to incredible levels of detail that Russel T Davis and his creative team were willing to go to, to make sure Doctor Who was an immersive and fleshed out experience.

RELATED: Doctor Who: Steven Moffat's Best Episodes, Ranked

If you look very closely on the wall full of posters seen in the episode ‘Father’s Day’ while Rose is waiting to save her dad, you’ll see a yellow poster with the word ‘energize’ on it. In faint writing, the words ‘Bad Wolf’ are scrawled over the top.

The Isop Galaxy

Despite the revival of Doctor Who technically acting as a follow up to the forty years of the show that came before, it didn’t reference it much. Russel T David decided to keep things simple by mostly remaining on earth and removing the Time Lords from existence entirely.

However, he didn’t cut people off entirely from the olden days. In the episode ‘Bad Wolf’, the Anne-Droid (more on that in a second) asks Rose “who is the oldest being on The Isop Galaxy?”. This planet hadn’t been mentioned since 1965, but the superfan writers managed to sneak in a little reference for the most clued up Doctor Who fans to find.

UK TV References

Doctor Who Weakest Link

This particular Easter egg is either incredibly obvious to British viewers, or totally obscure to everyone else. A large amount of the premise behind the episode ‘Bad Wolf’ is that The Doctor, Rose, and Jack are on a massive TV station each taking part in a well-known show that transmits across the galaxy.

RELATED: Doctor Who: Every Actor Who Played The Doctor, Ranked By IMDb Average

However, what you either definitely 100% knew or definitely 100% didn’t know, is that each show is a parody of a British classic. The Doctor is stuck in Big Brother (with host Davina McCall lending her voice), Rose is on The Weakest Link (with the Anne-Droid being voiced by Anne Robinson, and Jack is on What Not To Wear (with Trinny and Susanna playing the robot versions of themselves).

Bad Wolf TV

John Barrowman as Captain Jack Harkness in Doctor Who

Staying with the same episode for the third time in a row, you may notice that the TV channel everything in ‘Bad Wolf’ is taking place on is called Bad Wolf TV.

This acts as a bit of a misleading device for the audience, who may simply assume that all of those Easter eggs leading up to now were just referencing a TV channel. How wrong you were...

The Dalek Emperor’s Guards

The first time the Emperor Dalek was ever seen was way back in 1967, where Patrick Troughton encountered the huge, immobile form of the Dalek leader, surrounded by his guards. In a way, you could say that ‘The Parting Of The Ways’ is an Easter egg in itself by simply including the Emperor.

RELATED: Doctor Who: 10 Most Shameless Things The Companions Have Ever Done

However, look directly at his floating guards; they have blackheads. This is a nod to their design from all those years ago, in which the Daleks (who were silver and blue back then) who guarded the Emperor had blackheads.

Bad Wolf One

One final reference to Bad Wolf can be found in the episode ‘Dalek’, where the helicopter can clearly be heard saying ‘Bad Wolf descending’.

This suggests that the helicopter is called Bad Wolf. It must get pretty confusing to live in a wolf where about a million things have the same name.

A Future Easter Egg

Clara looking serious in Doctor Who

This Easter egg sort of works in reverse. It isn’t actually from the tenure of the Ninth Doctor but references something that happened during his time frame. Far later in the show, we meet Clara Oswald, and during the episode ‘The Rings Of Akhaten’ find out that her mother died on the 5th of March 2005. This was the exact day that the Autons invaded Earth and forced The Doctor and Rose to work together for the first time.

Throwing in this little retrospective Easter egg has a lot of implications, the main one being that she was killed by the first enemy we ever saw The Ninth Doctor face. Maybe we even saw her on-screen during the episode?

NEXT: Doctor Who: 10 Best Cybermen Stories (So Far)