Pumpkins. Candy. Costumes. All of these words may cause images of Halloween to come flooding into your mind. But behind all the cute and fun traditions that are practiced on Halloween, there is another side to this holiday that demands attention. That is the scary side! Halloween is a time for those who love horror to divulge in all things frightening.

During Halloween even the most innocent of things can morph into something horrifying. The best example of this is clowns.

Clowns have been warped and twisted into horrifying characters for years now. Fear of clowns can be so intense for some people that they might actually suffer from what is known as coulrophobia.

So what makes a clown absolutely terrifying? Could it be the makeup? The permanent smile? The unnerving, big red nose? Even though some of these reasons sound silly, it is hard to deny that there have been some creepy clowns throughout the years. Here is a list of four clowns, old and new, that have left people hiding in the corner in the fetal position.

1) “Killer Klowns from Outer Space” – This list starts off with a group of clowns from a movie that is more playful in nature than horrifying. “Killer Klowns from Outer Space” features a troupe of several clowns who terrorize a city by kidnapping and killing people.

The clowns in this movie are actually aliens in disguise, which is why no one believes that they could be serious murderers. Because who could believe that innocent clowns would be responsible for heinous crimes such as kidnapping and murder?

Despite the movie being very ’80s and the clowns trying to appear innocent, their creepy appearance, and malicious use of cotton candy in their killings, is enough to land them on this list.

2) Pennywise the Dancing Clown – It would be a crime to do a list of clowns and not include Stephen King’s famous clown Pennywise from “It.” Many would attribute their coulrophobia to this menacing clown who terrorized a group of kids in a fictional town called Derry, Maine.

The onscreen version of this terrifying clown was brought to life by Tim Curry. Although this clown preys on all the kids, his main focus is the lucky seven — a group of friends who live in Derry. Pennywise stalks and terrorizes these kids even in adulthood when they all finally return to town in an attempt to defeat Pennywise.

Pennywise’s antics range from balloons filled with blood to luring children down into the storm drain during bad weather. Thanks to King and Curry, Pennywise is one of the most well-known horrifying clowns.

3)  Twisty – A newcomer to the ranks of scary clowns is one that even has professional clowns up in arms. Twisty is the clown from Ryan Murphy’s “American Horror Story” (AHS). Since the season of AHS is still unfolding, it is still unknown what other horrors Twisty will release.

So far this season he has been a violent murderer and kidnapper, preying on specific types of victims. Twisty also hides a disfigured face under his mask which leaves more than a few people feeling sick to their stomachs. It is no doubt that Twisty will be some definite nightmare fuel for years to come.

4) Gurdy – Gurdy is a clown that might not be as well known, although this fact makes him no less terrifying. Gurdy is a clown featured in the movie “100 Tears,” which came out in 2007. The story focuses on Gurdy the clown, who is a well known stage performer.

Gurdy becomes enraged when he is falsely accused of committing a crime. The movie shows Gurdy’s dark side when two reporters begin following him to get the full story, and they ultimately become trapped in his warehouse. The reporters are left to fight for their lives against the murderous and vengeful Gurdy.

So whether you’re a fan of being terrified or suffer from coulrophobia, this list will help you to find (or avoid) terrifying clowns this Halloween.