For more than 60 years, the BBC's Doctor Who has kept the universe safe from monstrous threats in space and time. With almost 900 episodes to date, it's no surprise there have been certain alien races and creatures that pop up again and again across the decades, proving their own deadliness over and over. Here’s our ranking of Doctor Who’s adversaries by just how adversaries they truly are.

The most dangerous Doctor Who monsters - TL;DR ranking

1. The Time Lords
2. The Daleks
3. The Cybermen
4. The Weeping Angels
5. The Silence
6. The Zygons
7. The Sea Devils/The Silurians
8. The Sontarans
9. The Autons
10. The Ice Warriors
    
    

The most dangerous Doctor Who monsters - full countdown ranking

#10: The Ice Warriors

• First appearance: ‘The Ice Warriors’ (1967)
• Best story: ‘The Seeds of Death’ (1969)

Four years before David Bowie sang about Life on Mars, there was proof of it on television screens across the United Kingdom, thanks to the Ice Warriors — refugees from the red planet hibernating in secret on Earth in advance of a planned invasion to flee their dying homeworld. Unlike many Doctor Who monsters, though, there’s a happy ending for the Ice Warriors if you can navigate the confused timeline of a time travel series: they eventually become members of the Galactic Federation, and even assisted the Third Doctor at some point in the future. Their future, I should clarify, not the Doctor’s future.

#9: The Autons

• First appearance: ‘Spearhead from Space’ (1970)
• Best story: ‘Terror of the Autons’ (1971)

What’s more terrifying than an alien race that’s a creepy organic monster? An alien consciousness that can only possess plastic, and therefore turns anything made out of plastic — including mannequins and dolls! — into creepy non-organic monsters! If that sounds a little bit silly, then… okay, the Autons (technically the name given to plastic animated by something called the Nestene Consciousness) were slightly silly, as their trick of opening their hands to reveal hidden guns made clear. But just because they were ridiculous, that didn’t make them also somewhat unsettling. There’s a reason this was the monster that relaunched the series with 2005’s ‘Rose,’ after all.

#8: The Sontarans

• First appearance: ‘The Time Warrior’ (1973)
• Best story: ‘The Time Warrior’ (1973)

A race of genetically engineered clones created for war, the Sontarans are nearly invincible and invulnerable unless their enemies know of the “phobic vent” weakness on the back of their necks. (Everyone needs an Achilles’ Heel, even if it’s on their neck.) Created as a commentary on human conflict by writer Robert Holmes — who had both the Vietnam War and a classic piece of strategic writing titled On War on his mind — the squat, potato-headed creatures would become more comedic characters in more recent appearances. Despite that, they were still deadly foes on the battlefield.

#7: The Sea Devils/The Silurians

• First appearance: ‘’Doctor Who and the Silurians’ (1970)/'The Sea Devils’ (1972)
• Best story: The War Between the Land and the Sea (2025)
  

If the Ice Warriors were hidden alien monsters hibernating inside the Earth, then the Sea Devils and their land-based brethren the Silurians are the same thing but not aliens. Nope, they’re from Earth and they want you to know that the planet belongs to them, really; it’s just that they’d put themselves to sleep to avoid being annihilated by a catastrophic event. They periodically return in various Doctor Who adventures to threaten to reclaim the planet and/or make humanity extinct, working from the universally acknowledged ‘Finders Keepers’ rationale.

#6: The Zygons

• First appearance: ’Terror of the Zygons’ (1975)
• Best story: ’The Zygon Invasion’/‘The Zygon Inversion’ (2015)

Shapechanging aliens whose true ambitions seem to go no further than conquest, there’s something pleasingly inevitable about the Zygons — especially considering that, in their first appearance, one of the things they decided to change their shape into was nothing less subtle than the Loch Ness Monster. By the time they were revived in the 2010s, they’d scaled back their ambition with a long-game invasion that involved hiding in Gallifreyan paintings, and then simply replacing the Doctor’s companion when he wasn’t paying attention. See? They can learn.

#5: The Silence

• First appearance: ‘The Impossible Astronaut’ (2011)
• Best story: ‘Day of the Moon’ (2011)

The second of Steven Moffat’s high-concept Doctor Who monster hits — we’re about to get to the first, don’t worry — the Silence have an appropriately scary core concept: you immediately forget they exist when you’re not looking directly at them, so they can get up to anything and you’d have no idea. That they can also hypnotize and manipulate people without them realizing just makes them all the more frightening. What if we’ve all met the Silence at some point, and couldn’t remember it?

#4: The Weeping Angels

• First appearance: ‘Blink’ (2007)
• Best story: ‘Blink’ (2007)

The Weeping Angels are such an impossibly strong concept that they became an instant addition to the Best-of-Who canon on their first appearance: aliens that will literally steal your life — and throw you through time in the process — and are hiding in plain sight while they prepare to do it. The mix of mundane (we’ve all seen those statues, right?) and maleficence is unavoidable, and seeing that the Doctor himself couldn’t protect himself from them the first time around makes them even more appealing. No wonder that fans immediately wanted more after their first outing.

#3: The Cybermen

• First appearance: ‘The Tenth Planet’ (1966)
• Best story: ‘World Enough and Time’/‘The Doctor Falls’ (2017)

Before there was Star Trek’s Borg, there were the Cybermen: cyborgs who assimilate others into their number, often against their will. The concept has been rebooted and repurposed multiple times inside Doctor Who canon — They’re aliens who wanted to upgrade! They’re alternate reality humans who have tried to use technology to better themselves! They’re an army of the dead resurrected as artificial intelligence! — but at the core, it’s a simple idea: when we turn to technology to “improve” nature, bad things can happen unless we pay attention to the moral limits of such efforts.

#2: The Daleks

• First appearance: ‘The Daleks’ (1963)
• Best story: ‘Dalek’ (2005)
  

The iconic Doctor Who monster, the Daleks are unstoppable, genocidal creatures that have sacrificed everything to their hatred — including their own physical forms. That they happen to look so ridiculous is part of their appeal, and it’s also a fun underscoring of some Who subtext: don’t judge a book by its cover, because even wheelie bins with plungers for arms can be evil. The Daleks also have a unique position amongst the many Doctor Who monsters throughout the show’s 60+ year history: they have an easily recognizable catchphrase that managed to make it out of the show’s fanbase to become recognizable at large: EX-TERM-IN-ATE. 

#1: The Time Lords

• First appearance: ‘The War Games’ (1969)
• Best story: ‘Hell Bent’ (2015)

There’s an argument to be made that the Time Lords aren’t actually a monster in the sense that other Doctor Who monsters are; after all, it’s what the Doctor himself is, and he seems pretty cool, right? Of course, his good works could potentially be cancelled out by the Master, the Rani, and any number of other evil Time Lords that have popped up during the show’s run: Rassilon! The War Chief! Omega! Heck, even the Valeyard — an evil alternate future Doctor — for that matter. If you also factor in the destruction caused by The Time War, then let’s be real: the Time Lords as a whole are probably the most destructive race in all of Doctor Who lore. 

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