Doctor Who: 10 Most Underrated Villains And Monsters

Perhaps one of the few monster effects that can top how laughable Kroll looks are those for the Vardans. First appearing on-screen as beings of pure energy, they resemble see-through shower curtains or tinfoil more than villains that could pose a true challenge to the Time Lords. But here we have yet another classic Doctor Who monster where the intriguing concept at the heart of them is enough to overcome any questionable special effects.

The Fourth Doctor, Leela and K9 land on Gallifrey where the Doctor claims his right to the vacant position of Lord President and welcomes the Vardans into the Citadel, calling them the planet's new masters. But this is actually all a ruse by the Doctor to trap them in a time lock.

However, when he lets down the forcefield surrounding Gallifrey and tricks them into the lock, the Sontarans soon appear instead, revealing that they were using the Vardans to breach the Time Lord defences all along. Oops.

The Vardans being able to travel along any form of wavelength, including thought, makes them a truly unique villain and the existential threat they pose to the Doctor is unlike any other before them. While they do vanish from the story rather unceremoniously, their initially unknowable nature and formidable powers make them a worthy candidate for a return to the series.

Let's just hope their effects are a little better next time.