Doctor Who remains one of the longest-running series on television, and still holds the title of longest running science fiction series period. For almost sixty years, Doctor Who has given audiences some of the best –and, frankly, some of the worst– villains of all time.

With a hero as captivating as the Doctor, the villains need to meet the challenge. There are often easily defeated foes that only appear for an episode or more, but some of the best are those that have stuck around almost as long as the show itself. Looking back through both the classic run and the revival, here are some of of the scariest villains in the show’s history.

Rassilon And The Time Lords

Although the Doctor comes across as an incredibly benevolent being, his Time Lord counterparts are often another story. The high council and their leader Rassilon have remained some of the most ruthless of the Doctor’s adversaries. Steeped in tradition and power, their moral compass has often pointed in the opposite direction of the Doctor’s.

Although not every Time Lord-centric story is the best, they always serve as a fascinating foe for the Doctor. They are the mirror image of the titular hero, embodying his/her worst qualities. They use their power to rule over others, often with an iron fist. Rassilon’s ruthless nature, portrayed wonderfully by Timothy Dalton in “The End of Time,” embodies this perfectly. The Time Lords care about one thing and one thing only: the preservation of their way of life, at all costs.

The Cybermen

The Cybermen are one of the Doctor’s oldest enemies. First appearing in William Hartnell’s “The Tenth Planet,” The Cybermen are a race of beings who had removed all emotion from themselves to become more pure and calculating. Throughout their tenure, Cybermen have hailed from both the planet Mondas and (more often) Earth.

Some might find this placement surprising, but these foes have not had the best track records in regards to episode quality. Often they fall victim to lazy writing, which makes them feel like diet Daleks. Luckily, when these metallic terrors are done right, they shine. Embracing the body horror (especially of the Mondasian Cybermen in Peter Capaldi’s final season) fully displays their grotesque nature. Also, the Mondasian design is far more unnerving, with their soul-less eyes and moving mouths.

The Beast

Without a doubt, one of the greatest episode arcs of the entire revival was “The Impossible Planet/The Satan Pit.” This two-parter was unlike anything ever seen in Doctor Who. It embraced a much darker tone than anything seen in the revival at that point in the best way. The best inclusion, though, was the horrifying introduction of none other than Satan himself.

The blend of the fantastical with traditional science fiction hearkened back to Ridley Scott’s vision of the original Alien, but with hints and homages to the paranormal genre. Doctor Who turned a space outpost into a haunted house and it somehow worked. Satan felt like a villain who could appear anywhere and invade the minds and secrets of everyone, and that’s what made him so scary. Although this was his only appearance, The Beast made an impact that is still remembered to this day.

The Weeping Angels

Equally iconic and horrific, the Weeping Angels are one of the rare Doctor Who villains to surpass the show in reputation (the only other ones being the Daleks and Cybermen). Created by Stephen Moffat, these creatures are living statues that can send individuals back in time. The only catch is they can’t move if you see them. That little caveat is somehow both comforting and unsettling.

There is an argument to be made that their appearances have occasionally been overused, but even so, their presence alone sends chills down the spine of viewers everywhere. Obviously, their most significant role remains series four’s “Blink,” but they have remained solid (pardon the pun) throughout their subsequent appearances.

The Vashta Nerada

The Vashta Nerada made for one of the best one-off Doctor Who villains. In the season four two-parter “Silence in the Library/Forest of the Dead,” the Doctor and his companion Donna travel to a planet-sized library haunted by these microscopic creatures. The Vashta Nerda burst from spores within the pages of the books, whose paper was made from the trees of their homeworld. These invisible beings are essentially airborne piranha who can only travel in shadows.

Of course, these monsters were a product of Steven Moffat. As a writer, Moffat loves turning childhood fears into reality. These were some of his best creations, embracing the primal fear all beings have of the dark. A bonus to their innate scariness is their empathetic quality. These beings were a product of deforestation and displacement. It’s one thing to make a villain scary, but another thing to make them sympathetic.

The Zygons

The Zygons are one of the most underrated villains in all of Doctor Who. First appearing in the Fourth Doctor adventure “Terror of the Zygons,” The Zygons were a race of shape-shifting aliens who could take the form of any human at will. This was their only appearance until the 50th anniversary special in 2013, when the Zygons made an unexpected but welcome return to the series. Since then they have appeared once more in a Capaldi two-parter and have cemented themselves as one of the best-utilized villains in all of Doctor Who.

Their innate secrecy and subversion make their stories full of incredible twists and turns. Their appearance alongside Capaldi’s Doctor was arguably their best, serving as a pitch-perfect critique of violence, bigotry, and war. Hopefully, the gap between their next appearance won’t be as long as after their first.

Davros

Davros has remained a thorn in the Doctor’s side for a long time. The creator of the Daleks appeared for the first time during Tom Baker’s run. The story, “Genesis of the Daleks,” remains one of the most beloved of the entire series. Since then, Davros has wreaked havoc across time and space.

Multiple actors have taken on the role, but Julian Bleach has remained the only version for the revival. Although classic Who portrayals had great actors behind them, the combination of better prosthetics and Julian Bleach’s powerful delivery has secured Davros as one of the best villains in the history of the show. Davros condemning Ten as “the destroyer of worlds” and his and Twelve’s interactions are some of the best villains moments in the whole show.

The Midnight Entity

One of the most subversive moments for a Doctor Who writer, “Midnight” remains one of Russell T. Davies’ best episodes. Set on the planet Midnight, the Doctor takes an excursion to view a waterfall made of sapphires along with a band of other tourists. These visitors are believed to be the only lifeforms on an otherwise lifeless planet. They were wrong.

The Midnight Entity plays a similar role to The Beast in the “The Impossible Planet” arc, but audiences never truly see it. Its ability to take control of another living soul is a scary thought, but the process in which it gains agency is even scarier. The Midnight Entity plays upon some of humanity’s worst fears, from tribalism to the loss of agency. It brings these heady ideas into a miniaturized setting aboard this pleasure cruise. The Entity itself and this episode provide some of the most claustrophobic and scary moments in the whole series.

The Master/Missy

There was no one else who could take this spot. The Master is the Moriarty to the Doctor’s Sherlock. It’s the ultimate duality between hero and villain in the series. Though their stories have not always been perfect, the character itself has always provided nuanced characterization no matter the actor. It’s one of the most varied roles in the entire series.

Many actors have played the villainous Time Lord. Roger Delgado was the first, embracing a coy and evil persona which matched Jon Pertwee’s hero. Throughout the classic series, others eventually brought more to the part, including Anthony Ainley’s charisma and Peter Pratt’s insanity. The revival included the brief appearance from Derek Jacobi and the maniacally energetic John Simm. Michelle Gomez’s Missy soon became one of the most beloved villains in the entire series. A subtle yearning for compassion buoyed her psychotic Mary Poppinsshtick.

The Daleks

No other villain could hold the number one spot. It had to be the Daleks. These little salt and pepper shakers have been around longer than any other villain on this list. No matter how often fans gripe at their overuse, audiences still welcome them back when they’re gone for too long. Their design is as iconic as the TARDIS itself, and they’re also an essential element to this series.

Beyond their iconic status, The Daleks stories are some of the most memorable of the series. Their first ever story, simply titled “The Daleks,” changed the course of Doctor Who forever by introducing its first alien foe. “Dalek” in 2005 remains one of the most powerful Dalek stories yet, giving the domed devils a bit of humanity. Even when their stories are awful (“Daleks In Manhattan”), they still bring that quintessential Doctor Who magic.