BBC's Doctor Who is one of the longest-running science fiction shows of all time. Since 1963, the titular Doctor has been portrayed by 13 different full-time actors, met countless aliens, and visited countless alien worlds. Despite the extensive length of time that the show has been running, the showrunners have no difficulty in inventing new and compelling aliens, some of which can even rival the classic aliens of the Daleks and the Cybermen. That being said, this extensive past has also led to some truly awful aliens appearing on our screens, with a surprising number of which coming from the new era of Doctor Who.
This article will list the five best aliens the Doctor has encountered, and the five worst to balance it out.
Best: Dalek Emperor
While not necessarily one of the greatest characters in the history of the show, the Dalek Emperor is easily one of the coolest and most memorable. The character first appeared in the final story of the Ninth Doctor's run, appearing in charge of a gigantic Dalek fleet.
While the Dalek Emperor would only make this one appearance, he is one of the most memorable villains of the new Doctor Who era, so let's hope he comes back.
Worst: Adric
Adric was a companion to the fifth Doctor and one of the most hated characters in Doctor Who history. A boy genius, Adric wasn't afraid to voice his own opinion, even if doing so directly contradicted what the Doctor was telling him to do at a certain point in time.
Adric would go on to sacrifice himself in order to prevent a ship from crashing into Earth and killing the dinosaurs. He was not missed.
Best: Midnight Entity
"Midnight" may be one of the most underrated episodes of Doctor Who. In the same vein as "Blink," "Midnight" was a single episode that was very horror-focused and featured a new alien threat that viewers had never encountered before. The entity lived on an allegedly uninhabited planet named Midnight and possessed people abroad an exploratory tourist craft, including the Doctor.
Unlike the Weeping Angels from "Blink," we never see this alien again. Perhaps this mystery surrounding the creature is what makes it such a terrifying and fantastic alien villain.
Worst: Gibbis
While this character only appeared in one episode, he was one of the most infuriating and annoying characters to ever grace the show. Gibbis, played by David Walliams, was from the planet Tivoli, and a member of a species that takes a strange enjoyment out of being subjugated by other races.
The most infuriating part of this alien was his sniveling cowardice, and it was this cowardice that cost the life of another character.
Best: The Beast
The Beast, much like the creature from "Midnight," only appeared in one Doctor Who story. In the two-parter "The Impossible Planet," the Doctor meets a terrifying creature that he claims to be the actual Devil. This creature was not only a terrifyingly monstrous beast, but was also able to possess individuals, with an archaeologist named Toby being the victim of this.
While the CGI may be slightly out of date now, there is no denying that the Beast was a memorable villain.
Worst: The Kandyman
While not an organic life form, the Kandyman ought to still be included on this list as he did originate from another planet. Appearing during the Seventh Doctor's run in the series, the Kandyman was an insane assassin who was obsessed with killing its victims in candy-related ways.
Due to its horrific design based on the British confectionary manufacturer Bertie Bassett, many fans despise the Kandyman and believe it to be a symptom of the show's decline in quality during the 1980s.
Best: Davros
Davros is one of the most iconic Doctor Who villains of all time, with the creator of the Daleks appearing in several influential and memorable stories over the years, such as "Journey's End." Whenever the character appears, it will always lead to an intense and memorable story.
The most recent return of Davros came during Peter Capaldi's era, and added an incredible amount of much-needed backstory to the villainous character.
Worst: Vorg
Vorg was an alien collector who accidentally captured the TARDIS using an illegal device that the Doctor had worked to outlaw. While Vorg would still go on to help the Doctor later in the episode, showing that he isn't evil, he deserves a place on this list for one main reason: his outfit is one of the worst atrocities we've ever seen on Doctor Who — and that's including anything the Master has done.
Best: The Master
The Master is the Moriarty to the Doctor's Sherlock. While the Daleks and the Cybermen always pose a more brute force challenge for the Doctor, the Master always offers a greater puzzle, acting as a dark mirror to the titular Time Lord himself. Despite being a part of the show for several decades, we still know very little about the antagonist.
We know that the Master and the Doctor used to be friends, adding a more personal note to their stories, but aside from this we know little. The mystery deepens even more with Sacha Dhawan's version of the character as fans don't know if this incarnation is pre or post-Missy.
Worst: Abzorbaloff
It's impossible to list the worst Doctor Who aliens without including the Abzorbaloff. The Abzorbaloff was designed by a child who won a children's TV program competition and, without any disrespect to the winner, anyone could guess that this monster was designed by a child.
That being said, it wasn't just the design that was awful about this creature; the episode he starred in is also notorious among Doctor Who fans as being one of the worst ever produced.