If there’s one thing that definesDoctor Whoas a series, more so than its heroes or its fantastical settings, it’s the monsters. Each new episode brings a fresh horror for us to gawk and gasp at, many of which pushed the boundaries of special or practical effects at every stage of the series’ long run.
Many of these, such as the Daleks, Cybermen, and Zygons, have enjoyed frequent returns in episodes of the modern series, but many others haven’t been quite so lucky. Today, we’re celebrating those unsung villains: the monsters that molder under the couches of time, longing to terrify a new generation.

10The Mandrels
Last Appearance: Nightmare Of Eden, 1979
A striking monsterfrom the Fourth Doctor era, the Mandrels are notable for two reasons: their excellent visual design, and their unique connection to in-universe drug vraxoin. As natives of the jungle planet Eden, the Mandrels are ordinarily a fairly passive species, but the vraxoin they release on death makes them sought after by opportunists the universe over.
Nightmare in Eden, the first and only appearance of the Mandrels, explored the theme of drug trafficking well, but there’s more that could be done with such a monster in a new, modern context. Next time Doctor Who wants to reach for the social commentary, they should crack open the Mandrels.

9Sutekh
Last Appearance: The Pyramids Of Mars, 1975
Monsters in Doctor Who run the gamut from minor to major, and Sutekh is firmly on the latter end of that spectrum. The last survivor of the mighty Osirian race, Sutekh is near-god like in terms of power, using his psychic abilities to play therole of main villainin Pyramids of Mars despite being physically frozen in place.
His immense power, and the in-depth lore around the Osirians in general, make Sutekh a prime candidate for a series big bad in the future. Rather than trotting out Davros or the Master again, Doctor Who should unearth this mighty warrior from his sandy tomb instead.

8The Krynoids
Last Appearance: The Seeds Of Doom, 1976
If you were to pick just one monster to serve as the face of Doctor Who’s flora, it would have to be the Krynoids: a species of galactic plants that grow from tiny seeds to world-devouring monstrosities. It’s a sci-fi classic, and one that could add some welcome variety to the show’s recent lineup of largely humanoid foes.
The idea of an invasive plant species slowly overtaking an entire planet is ripe for exploration, with a post-Krynoid jungle world being a rich potential setting. The leafy nature of the Krynoids could also allow for some natural exploration of ecological themes: a topic Who has tackled with mixed success in the past.

7The Fendahl
Last Appearance: Image Of The Fendahl, 1977
Also known as ‘The Darkness,’ the Fendahl is a terrifying 13-part organism that feeds on psychic energy, leaving its victims soulless husks. In addition to its central core, the Fendahl also has 12 Fendahleen, eyeless, worm-like monstrosities capable of flight and teleportation.
Despite only appearing in a single serial in 1977, the Fendahl is credited with the complete destruction of all life on several worlds, and the manipulation of human evolution through a stray skull left behind in prehistoric times. The unique structure of the Fendahl as a creature, and its huge capacity for destruction, makes it a brilliant choice for a high-stakes modern two-parter.

6Axos And The Axons
Last Appearance: The Claws Of Axos, 1971
With their tangled, spaghetti-like design, the Axons embody the unique charm of classic Doctor Who monsters perfectly. They also have an interesting narrative side, collectively forming a single parasitic organism that seeks to master the secrets of time travel and go on to drain the energy of countless worlds.
Doctor Who has explored hive-mind creatures before and after the Axons, but something about their simple designs, and the intrigue provided by their deceptive angelic forms, make us long to see them on screen again. If nothing else, their connection with The Master could help set up some interesting modern adventures.

5The Destroyer
Last Appearance: Battlefield, 1989
Battlefield was an interestingSeventh Doctor episode, simultaneously bringing Arthurian legend to the world of Doctor Who while also greatly expanding the mythos of the Time Lords. At the center of the episode lurked The Destroyer, a powerful demon summoned by the sorceress Mograine.
Though very powerful, The Destroyer had a weakness to silver: a hallmark of many classic monsters. With upcoming series’ of the show looking to lean more heavily into fantasy following the 14th Doctor’s salt-scattering antics at the edge of the universe, it could be the perfect time for this blue-skinned beastie to make a return.

4The Kroll
Last Appearance: The Power Of Kroll, 1979
Some Doctor Who monsters are great because they cleverly reflect aspects of human nature, making us consider ourselves in a new light once they’re done terrorizing the TARDIS crew. Others are great because they provide the kind of spectacle you just don’t see much on TV. The Kroll is firmly in the spectacle category, and its return is long overdue.
The Kroll is very simple in concept. When you dig down into it, it’s really little more than a giant squid. But sometimes a giant squid is all you need to provide the setup for a cracking action-focused episode.

3The Ogri
Last Appearance: The Stones Of Blood, 1978
Of all the bizarre creatures The Doctorand their companionshave faced on their travels, the Ogri are in the upper echelons. Essentially, they’re sentient stones, slow to move but capable of draining the blood from their victims through touch if they manage to rumble their way up to them.
While their physical limitations make them tricky to slot into a modern Who story without feeling silly, in the right setting, like a tightly-constricted tunnel system, they could provide a feeling of creeping dread not unlike that of the Weeping Angels. They may be obscure, but the Ogri have serious potential both as a throwback and an exciting change of pace.

2Kandyman
Last Appearance: The Happiness Patrol, 1988
There’s a lot to unpack when it comes to the Kandyman. On one level, he’s a Bertie Bassett-esque candy creation that wouldn’t look out of place on the side of a pick n’ mix bag. On another, he’s a psychopathic killer that delights in bringing sugary death to anyone foolish enough to be caught unhappy on the world of Terra Alpha.
The Kandyman is a classic juxtaposition of a bright, childish aesthetic with a dark, gruesome undercurrent, and he’s ripe for further exploration in the grittier modern Who style. Though of course, if he were to return, they’d likely have to remove his hilariously crippling weakness to lemonade.

1The Krotons
Last Appearance: The Krotons, 1968
A monster so old it’s never appeared in color, the Krotons are, mechanically, quite similar to Daleks or Cybermen. What sets them apart, however, is their delightfully retro visual design, which combines hard crystalline edges with the aesthetic of 1950s kitchen appliances.
They’re great fun to look at, and possibly even quite funny, which could result in some lovely bait-and-switch moments when they show their true, threatening colors later on. While the Doctor’s core suite of metallic foes is solid, a wild card offering like the Krotons could do a great job of spicing it up.