Reference

In the long history of Doctor Who, several villains have made recurring appearances, challenging the Doctor time and again. Here are some of the most notable recurring villains:

1. The Daleks: Perhaps the most iconic of all Doctor Who villains, they are a race of mutated beings housed in tank-like mechanical casings. Their catchphrase, "Exterminate!", is infamous.

2. The Master: A Time Lord like the Doctor, the Master is his arch-nemesis and appears in various incarnations over the series.

3. The Cybermen: Initially human, these beings have replaced most of their body parts with cybernetics, aiming to convert all of humanity.

4. The Sontarans: A clone race bred for war, these potato-like warriors have often been both comedic and menacing.

5. The Weeping Angels: Statues that move when they're not being watched, they are both terrifying and fascinating.

6. The Ice Warriors: Hailing from Mars, the Ice Warriors are a race of reptilian humanoids who often have complex motivations.

7. The Zygons: Shapeshifters that can take on the appearance of any being they touch, these aliens have caused numerous problems for the Doctor.

These villains, among others, keep the Doctor and the audience on their toes with their recurring appearances and evolving threats.

For further reading, check out:

• Space.com - Doctor Who Villains, Ranked
• Screen Rant - Doctor Who's Big Villain Reveals, Ranked