Across the decades of rich history Doctor Who has enjoyed, there have been a handful of villains that repeatedly show up. Daleks, Cybermen, Davros, Sontarans, Zygons, even the Time Lords. One villain has stood out amongst them all, the Doctor's very own childhood friend, a fellow Gallifreyan known as the Master.

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The Master has featured in tons of episodes throughout the show's run, played by a plethora of actors just like the Doctor. Some of the Master's appearances have been better than others, but all have contributed to the character's enduring popularity amongst Doctor Who fans all across the world. It's just a shame the Master hasn't yet featured in a Doctor Who game.

10 The End Of Time: The Master Becomes Everyone

Promotional image of The End of Time from the show Doctor Who.

The End of Time is a double-episode that offers a very strong closing story for the Tenth Doctor (David Tennant), but a mixed bag for the Master. The Master (John Simm) has a lot of great moments, with lots of interplay with the Doctor allowing Simm and Tennant to shine in personal, Gallifreyan-centric dialogue. It does, however, take the Master and turn him into something from a forgotten superhero show, so it's sort of a mixed bag.

Unfortunately, it also features the Master flying, shooting electricity out of his hands, and becoming everybody on Earth, and cackling endlessly. The silly, superhero-esque development of the Master's character doesn't tarnish the great moments he has throughout the story; culminating in his heroic moment stopping Rassilon and the Time Lords from returning.

9 Survival: Cheetah Master

Promotional image of Survival, a serial from the TV show Doctor Who.

Survival features the Master (Anthony Ainley) going toe-to-toe against the Doctor (Sylvester McCoy) while allied with the Cheetah People. On a planet that affects those living on it, first offering them feline characteristics before transforming them completely into Cheetah People, the Master draws the Doctor and Ace into grave danger.

For many Doctor Who fans, this is seen as the serial which has Ainley's incarnation at his best; differentiating him from being a rehash of the Roger Delgado version. While the plot may seem a little silly at times, Ainley's portrayal makes up for it. Fans of Skyrim Khajit characters will enjoy the Cheetah People aspect of Survival.

8 The Mind Of Evil: Suave And Masterful

Promotional image of The Mind of Evil, a serial from the TV show Doctor Who.

While The Mind of Evil may not be as flashy or fast-paced as the Master's more modern appearances; it informs a lot of the chemistry explored between the Doctor and the Master in the new series. The Master (Roger Delgado) is at his most suave, in quiet control throughout the serial until his plans come crashing down around him in a comical fashion.

The serial features a lot of interplay between the Master and the Doctor (Jon Pertwee). Arguably these scenes paved the way for a lot of modern interactions between the two, making The Mind of Evil one of the Master's best.

7 The TV Movie: The Enemy Within

Promotional image of the TV movie The Enemy Within, a movie from the TV show Doctor Who.

The TV Movie has received mixed reactions ever since it was released. The general consensus on fans is that Eric Roberts overplayed his incarnation of the Master, but fan opinion on whether that's a good thing is polarized. It does however see the Master causing a serious threat, even leading to him using the Eye of Harmony for his nefarious schemes.

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The Master manages to cling to life after being executed on Skaro; and his plans threaten the entire universe, giving the newly regenerated Eighth Doctor (Paul McGann) plenty to do. Defiant to the last, the Master refuses to take the Doctor's hands and have his life saved, presumably dying at the end of the episode. This Master's inclusion was a great feature for the Eighth Doctor's first episode.

6 Utopia: A Resurgence In The Character

A promotional image of Utopia, an episode from the TV show Doctor Who.

Utopia doesn't feature the Master until the final ten minutes of the episode; but it is a brilliant reintroduction for the character into the modern show, after a decade of absence. Professor Yana activates the fob watch he's had since birth and unleashes the Master (Derek Jacobi)'s consciousness.

Killing his assistant Chan Tho, and stealing the Doctor (David Tennant)'s TARDIS, the Master quickly lands the Doctor and co in grave danger. Shot back by a dying Chan Tho, he resentfully regenerates into the John Simm incarnation, before using the Doctor's TARDIS to travel back to the 21st century.

5 Death in Heaven: Missy's Birthday Present

Promotional image of Death in Heaven, an episode from the TV show Doctor Who.

Death in Heaven may not be the strongest episode overall, but it does feature a lot of great Missy (Michelle Gomez) moments that steal the show from the Doctor (Peter Capaldi). With a Cybermen army at her command, she willingly gets captured into UNIT custody, before brutally killing companion-to-be-Osgood.

It also turns out that the whole Cybermen army Missy has created is purely to offer to the Doctor as a birthday gift. It's a moment that encapsulates the quirky strain of insanity that Missy possesses. Unfortunately, the episode doesn't do much for the Cybermen, borrowing aspects from scary zombie movies.

4 The Magician's Apprentice: Missy As An Anti-Hero

Promotional image of The Magician's Apprentice, an episode from the TV show Doctor Who.

The Magician's Apprentice has loads going on, but still finds time to make Missy (Michelle Gomez) a huge part of the story, and something of an anti-hero. She gets Clara's attention by freezing all of the planes in the sky in time and travels in time with Clara in order to find the Doctor (Peter Capaldi).

Missy travels with them to Skaro, which has her become an antihero because she hates the Daleks more than she hates the Doctor and Clara offered a stepping-stone for Missy's later redemption.

3 World Enough and Time: Two Sides Of The Same Person

Promotional image of World Enough and Time, an episode from the TV show Doctor Who.

The precursor to The Doctor Falls, World Enough and Time features Missy (Michelle Gomez) at her very best; filling the role of the Doctor (Peter Capaldi) and aiming to do good rather than bad. Throughout the story, Missy assists the Doctor and Nardole until coming across Mr. Razor, who reveals himself to be the Master (John Simm) in disguise. The Mr. Razor disguise is one of the most impressive yet, reminiscent of characters from some of the best psychological horror movies.

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Having watched Mr. Razor interact with Bill over the course of many years, until eventually betraying her, his eventual reveal as the Master was shocking. It's the Master's ultimate insult to the Doctor, having his companion upgraded into a Cyberman. The juxtaposition between both Masters is perfect and goes down as one of the character's best appearances.

2 Last Of The Time Lords: The Master At His Highest

Promotional image of Last of the Time Lords, an episode from the TV show Doctor Who.

Last of the Time Lords sees the Master (John Simm) in full control of the planet. With millions upon millions dead, the Doctor (David Tennant), Captain Jack, and Martha Jones' family all captured, only Martha Jones can save the world. The Master is in full control during this episode, beginning the episode singing along to music and berating the Doctor, who is caged up.

There are tons of great moments for the Master during this episode; hunting for Martha in the deserted London streets, berating all of his imprisoned adversaries, his violation of the Doctor's TARDIS, even his final confrontation with the Tenth Doctor. The Master gets the last laugh, refusing to regenerate despite the Doctor's pleas, even though he is betrayed by the woman closest to him.

1 The Doctor Falls: The Master's Best Episode

Promotional image of The Doctor Falls, an episode from the TV show Doctor Who.

The Doctor Falls has two incarnations of the Master; John Simm and Michelle Gomez, fully acquainted and working together. Simm's incarnation berates and chastises Gomez's incarnation, pulling her back to the typical unsavory and villainous attitude the Master is known for. It's just a shame we never saw the Master's TARDIS console room.

The story comes full circle with Gomez's incarnation assassinating Simm's incarnation, who kills her back. Both incarnations laugh while they die together, in what could have been the most fitting end to the Master's character. Not only is it a great Master-centric episode, but it offers Simm much more mature material than he had during his initial appearances.

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