Aliens have long fascinated humans. We have been wondering about the possibility of life on other planets, of whether we are alone in the universe, for thousands and thousands of years. Even now, some people are still convinced the Great Pyramids of Egypt were built by alien hands rather than human: likewise, the origins of the monolithic statues of Easter Island remain a mystery.

The scientific search for extraterrestrial life began in earnest as humans developed technology powerful enough to potentially contact outer space. In 1896, Nikola Tesla stated publicly that he believed a version of his transmission system could reach as far as Mars; at one point a few years later, he briefly thought he had made contact.

Since then, the ‘do aliens exist’ debate has raged on, with scientists and conspiracy theorists from across the globe voicing their ideas and opinions. 

Aliens have also been prevalent in popular culture for decades, from puppets and ‘little green men’ to the intensely detailed CGI creations of modern TV and film. 

Some of these extra-terrestrial characters are more memorable than others. They might be friendly, or gross to look at, or determined to eliminate all of humankind – whatever we might imagine them to be.
Let’s take a look at some of the best.

The Heptapods
One of the more unusual alien-invasion movies of recent years is Arrival, starring multiple Academy Award-nominated actress Amy Adams as a linguist recruited to communicate with a pair of otherworldly visitors. The film was extremely well-reviewed on release, largely because of the fresh, new way that human-alien interactions were depicted. 

In fact, we don’t even really see the aliens – just their tentacles, which spray an inky substance that they ‘write’ their words with. We also know they’re pretty big, and they’re called heptapods. But that’s about it.
This heptapod pair, named ‘Abbott’ and ‘Costello’ after the comedy duo, are some of the most benevolent aliens we’ve ever seen in cinema. Unlike this next contender…

The xenomorph would be one of the most instantly recognizable aliens in all of cinema, even if you didn’t know its name. The central antagonist of the Alien series, the xenomorph’s long head, huge teeth, and incredible size, struck fear into the hearts of moviegoers around the world – despite appearing on screen for only four minutes of the franchise’s first film. A blind, cold-blooded killer, perhaps the xenomorph’s most terrifying characteristic was its tendency to use humans as incubators for its young. 

In one of the film’s most famous scenes (and one of the scariest in the history of movies), a baby xenomorph bursts from the chest of one of the main characters. Fun film trivia: when the scene was shot, the actors weren’t told that it would involve real blood and guts. Their reactions are completely genuine!
Released in 1979, the first Alien also made a Hollywood megastar out of 28-year-old unknown Sigourney Weaver and launched Ridley Scott’s directing career into the stratosphere. It also spawned one of the biggest and most enduring franchises we have ever seen, with new Alien movies still being released to this day.

Star Wars is probably the most iconic science-fiction series to ever exist, and Yoda is one of its most memorable and iconic characters. Making his first appearance in The Empire Strikes Back as the eccentric, ancient (he’s 900!) mentor to Jedi apprentice Luke Skywalker, Yoda was an instant hit. Dry-witted and odd-looking, Yoda’s impressive power, wisdom, unique speech pattern, and mysterious origins – we never find out the name of his species - proved a powerful combination. 

Originally a puppet and changed to a computer-generated character for the prequel trilogy, Yoda made his final appearance as a Force Ghost in 2017’s The Last Jedi, in a warm and humorous scene with former pupil Luke Skywalker. 

Yoda can also be seen on the small screen (sort of) in spinoff series The Mandalorian. It’s not actually him, it’s a character of his species known as ‘The Child,’ but the Internet has taken him to their hearts as ‘Baby Yoda.’ 

The Thing
Its name may be basic, but John Carpenter’s most famous creation is anything but. An Arctic-dwelling shapeshifter that preys on humans by literally turning into them, The Thing is not only one of the scariest cinema aliens ever, but one of the scariest characters of any species in the history of film. What do you do when any one of your friends could be a murderous alien in disguise? It’s no wonder this masterpiece regularly appears near the top of ‘greatest horror’ lists.

The Na’ vi are somewhat unusual amongst movie aliens as in Avatar; it is they who are persecuted and attacked by humans and not the other way around. Your typical alien invasion narrative this is not!

Much bigger than humans (they are around ten feet tall), the Na’vi live on the moon of Pandora, which has been colonized by humans. The human aggressors refer to the Na’vi, who are phenomenally beautiful, using several derogatory names such as ‘savages,’ ‘hostiles’ and even ‘blue monkeys.’ But the Na’ vi are a peaceful people, with a strong relationship with nature and their goddess Eywa, and the movie serves to make us reflect on the nature of humanity, technology, and discrimination.

When it was released in 2009, Avatar was a groundbreaking achievement, using computer-generated visual effects that had never been seen before, and a commercial juggernaut. It was the highest-grossing film of all time for a decade, grossing $2.79billion, before being dethroned by Avengers: Endgame in the summer of 2019. 

Rivaling Yoda for the title of ‘most adorable alien ever’ is E.T, the lost young extra-terrestrial of Steven Spielberg’s 1982 film. Stranded on Earth after his parents’ spaceship accidentally leaves him behind, E.T is befriended by a boy named Elliott – who makes it his mission to get E.T home. Over the course of the fil, they face several trials and challenges, but their friendship endures to the end – leading to one of the most tear-jerking conclusions of any movie on this list.

The idea behind the film, and the character of E.T, was to show an alien interaction through the eyes of a child. In fact, for most of it, the camera is so low that we could even be a child! E.T himself is ten million years old, according to the novel based on the movie, but his innocence and charm makes him timeless and endlessly loved by moviegoers of all ages. An extra fun fact: E.T’s face was modeled to be a blend of Albert Einstein and a pug. 

His human appearance means we often forget he isn’t one, but Superman was actually born on the fictional planet of Krypton and sent to Earth by his parents before the planet was destroyed. Crash-landing in the American countryside, Kal-El, or Clark Kent as he is better known, was adopted by a pair of farmers and raised as a human. It wasn’t until later in his life, when he began spontaneously developing superhuman strength and power that he noticed he was different.

Another of the more honorable aliens on our list, Superman uses his powers to fight crime and help humanity. Working a day job as a journalist and holding down a long-term relationship with Lois Lane, every so often, he whips off his glasses and work clothes and transforms into the cape-wearing wonder we know and love.

Even decades after his first introduction, Superman remains one of the most popular superhero characters of all time and has starred in comic books, video games, TV shows, and movies. What a guy!

Mr. Spock
Mr. Spock, or Spock to his friends, is one of the three main characters of the original Star Trek TV series (and a whole bunch of spinoffs, novelizations, movies, name it). Human at first glance until you notice those famous ears, Spock is actually half-human, half-Vulcan: a mixed heritage that provides the storyline for many of his best-known episodes.

In fact, Spock’s origins are seriously sci-fi; his mixed parentage meant that he was literally grown in a test tube for part of his mom’s pregnancy, before being put back into her womb near the end. Unsurprisingly, no other child had ever survived such a ‘WTF’ beginning. 

He was also badly bullied by his peers growing up; Vulcans are famously emotionless, and Spock’s ability to feel things were considered a weakness.
Originally played by the late, great Leonard Nimoy, Spock has also been played by Zachary Quinto and Ethan Peck. 

The Big Bad of the Predator and Alien vs. Predator movie franchises, these badass aliens burst onto our screens in the 1980s and continue to frighten us to this day. Taking on Arnold Schwarzenegger in the first movie of what is now a huge franchise, these guys had no interest in making friends, or even enslaving the human race. They just wanted us dead and had the weapons to get the job done.