When Russell T. Davies took the reins of Doctor Who's dramatic 2005 revival, he brought several changes to the series, including introducing a variety of new characters. However, he also opted to get back some classic friends and foes fans were already familiar with, ensuring diehard Whovians could see their favorite characters on screen again.

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As Davies' return edges closer, speculation is heating up around which familiar faces will be making their way back to the show from classic and modern eras. Conniving enemies who've been hiding in the shadows, one-episode wonders who deserve another appearance, or beloved companions are due an emotional return. All of these Doctor Who characters should come back to the show one way or another.

Osgood

Petronella Osgood (Ingrid Oliver) in Doctor Who

Petronella Osgood (Ingrid Oliver) was a scientist at UNIT and almost immediately became a fan favorite following her introduction in "The Day of the Doctor." Often sporting attire reminiscent of Doctors past, Osgood is easy to relate to and effectively a Whovian in her own regard.

Osgood and her Zygon double were last seen in Series 9's "The Zygon Inversion," which left audiences unsure whether the original human or her alien doppelgänger were killed at the hands of Missy. Either way, a return for Osgood would be a welcome one and could even be on the cards following her name-drop by Kate Stewart in 2021's "Survivors of the Flux."

River Song

Alex Kingston as River Song in Doctor Who

A return for River Song (Alex Kingston) could perhaps be controversial as many believe she was given the perfect send-off in 2015's "The Husbands of River Song." Anything can happen when time travel is involved, though, and River and the Doctor have a track record of meeting in the wrong order.

Kingston's performances as Professor Song saw her steal almost every scene she starred in, and although there was a dramatic beginning and emotional end to her story, there's still a whole chunk of the middle yet to be told.

K9

Robotic dog K-9 appearing in Doctor Who

The Doctor's robotic dog, K9, made his first appearance way back in "The Invisible Enemy" in 1977 and has since accompanied several incarnations of the Doctor and his companions, most recently Sarah Jane Smith (Elisabeth Sladen). Though it's been over a decade since K9 was last seen onscreen, he remains a beloved addition to the series and is always a massive hit with younger viewers.

Russell T. Davies brought him back once and could very well do it again, adding a hint of nostalgia as he looks to make the show appeal to hardcore Who fans and new audiences.

Susan Foreman

Susan Foreman (Carole Ann Ford) in Doctor Who

Doctor Who has come a long way since its first episode in 1963, but the basic theme remains the same; a bonkers alien traveling with their companions in a spaceship disguised as a police box. Though many aspects of the classic era are often revisited, there's been no word on the whereabouts of the Doctor's first co-traveler and apparent granddaughter, Susan Foreman (Carole Ann Ford).

David Bradley did a fantastic job of bringing the likeness of the First Doctor (William Hartnell) to 2017's Christmas special "Twice Upon a Time," and a return for Ford's character would be an epic throwback. It could play into the current mystery surrounding the true origin of the Time Lord.

Jenny

Georgia Tennant as the Doctor's daughter, Jenny, in Doctor Who
Image via BBC

From the Doctor's granddaughter to his daughter, of sorts. During "The Doctor's Daughter" (2008), Jenny (Georgia Tennant) was created from a DNA sample of the Tenth Doctor. Jenny seemingly met her demise when she jumped in front of a bullet aimed at the Doctor but came back to life and set off to explore the universe by the end of the episode.

Like many of these characters, Jenny's story has been revisited in Big Finish's audio dramas, she's yet to appear onscreen since her introduction. Russell T. Davies is famed for expanding the Whoniverse in the past, and if he's looking to create further spin-offs, Tennant would be the perfect candidate to lead a series.

The Vashta Nerada

Vashta Nerada in Doctor Who's Silence in the Library (2008)

Dubbed "piranhas of the air," the Vashta Nerada were some of the most feared yet most popular Doctor Who monsters. Introduced in the excellent two-parter "Silence in the Library" and "Forest of the Dead," the microscopic creatures hid in the shadows, waiting to prey on their next victim.

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The Vashta Nerada caused some of the most chilling scenes in the modern era, occupying the spacesuits of their deceased victims and making their skeletons walk. Given their immense popularity among Who fans, it'd be no surprise if these terrifying foes were reintroduced sooner rather than later.

The Dream Lord

Toby Jones as The Dream Lord in Doctor Who episode Amy's Choice

There are few episodes that left audiences feeling as uncertain as Series 7's "Amy's Choice" did. In a trick designed by the mysterious "Dream Lord" (Toby Jones), the Doctor, Amy and Rory had to choose between two dreams and decide which one was their actual reality.

Jones' performance set a template for anyone looking to take the role in the future, as he cleverly manipulated the Doctor and his companions and delivered a few home truths. Though the Dream Lord turned out to be a physic manifestation of Matt Smith's Doctor's inner, darker self, it'd be a missed opportunity not to introduce new versions of the character as part of future incarnations of the Time Lord's personality.

Martha Jones

Martha Jones

In a show filled with gut-punching goodbyes to its adored characters, the Doctor's companions rarely leave life on the TARDIS relatively unscathed. Martha Jones (Freema Agyeman) was one of those exceptions. Martha quit life as a time traveler after recognizing that her feelings for David Tennant's Doctor weren't reciprocated and made a few more appearances before last showing up in Series 4's finale.

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Presumably still alive, memory still intact, and not trapped in a parallel universe, Martha is a perfectly viable possibility for a future comeback, and it would delight Whovians worldwide.

The Rani

The Rani (Kate O'Mara) appearing in Doctor Who

Classic Who villain the Rani (Kate O'Mara) hasn't yet appeared in the modern era, but the Time Lady would be a perfect addition to the show. As a former enemy of the Doctor and ally of the Master, a return for the Rani would be huge, and fans have already convinced themselves of her return in the past.

Before Missy's reveal as the Master in Series 8, fans widely speculated that Michelle Gomez's character could've been a regeneration of the Rani. The gender swap proved to be a clever swerve, and a similar plot twist in the opposite direction could be as impactful when bringing back the Doctor's old foe.

Ninth Doctor

Christopher Eccleston as the Ninth Doctor in Doctor Who

Christopher Eccleston's run as the Ninth Doctor in 2005 shaped the future of the new era, and many regular viewers believe he has unfinished business as the Time Lord. After just one complete series, it looked like Eccleston's time in the TARDIS was over for good, but fans still live in the hope that he'll soon return to their screens and don the leather jacket once more.

Eccleston recently returned in audiobook The Ninth Doctor Adventures, sparking further talk among Whovians that he'll make his long-awaited return in an onscreen capacity. Though he's played down team-ups with fellow Doctors in the past, the 60th Anniversary is just around the corner and a televised return for Christopher Eccleston in some form should certainly not be out of the question.

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