We're all scared of something - right? But which of all the world's phobias is the most frightening of all? A fear of spiders? A fear of heights? A fear of food? There's a lot of scary stuff out there, but which phobia is the worst to have? And what even is a phobia in the first place? The fear factor doesn't disappear once Halloween is over, you know!

With new advancements in graphics come new ways to terrify! Welcome to WatchMojo, and today, we’re counting down our picks for the Top 10 Scariest Modern Video Game Bosses. For this list, we’re looking at the most frightening boss battles from current-gen games. Again, we’ll only counting titles from this generation, meaning anything prior to 2013 is out of the picture. Sorry, Mr. Freeze...you’re still the coolest in our book. Pun intended.

The singularity is nigh. For this list, we're looking at programs and experiments that show how alien, dangerous, or just downright creepy AI can be. While AI is making promising inroads into medical research, agriculture, and education, many experts also worry it could escape our control, or become catastrophic in the wrong hands. Welcome to WatchMojo, and today we're counting down our picks for the top 10 frightening developments in artificial intelligence.

Who needs sleep, anyway? Lying wide-eyed in bed is much more enjoyable. For this list, we're looking at the top 10 scariest ending scenes from horror movies.

The chills will never end. Welcome to MsMojo, and today we’re counting down our picks for the most devastating, frightening, and/or unsettling endings in film.

These dangerous movie dinos are not to be trifled with. Welcome to WatchMojo, and today we’re counting down our picks for the most frightening dinosaurs in film history.

These CGI movie monsters are horrifying, but not in a good way. For this list, we’ll be ranking the most egregious examples of computer-generated effects to offend our eyes, effects that were far more frightening than any monster.

In both the "Terrifier" movies and the anthology "All Hallow's Eve," Art the Clown absolutely petrified us. For this list, we’ll be picking out this hilariously terrifying clown’s most frightening moments across his movie appearances. Careful, there will be spoilers ahead.

These scares had us jumping out of our skin! For this list, we’ll be looking at the most frightening and effective movie jump scares in each year of the 21st century so far.

These terrifying creatures will haunt your nightmares! For this list, we’ll be looking at the most frightening monsters in movie history.

They may not have been labeled as horror, but these scenes are guaranteed to terrify you! For this list, we’re looking at the most terrifying, disturbing, and chilling scenes from movies outside of the horror genre.

Now that’s how you introduce a monster! For this list, we’ll be looking at the most shocking and most exciting monster reveals in film.

There's nothing more frightening than the unknown. For this list, we're looking at the scariest baddies that just don't get the same attention as icons like Jason or Chucky. We're basing our choices on a mix of ominous appearances, cunning plans, and the lengths each antagonist goes to for their plans. Our countdown includes villains from films such as "Behind the Mask: The Rise of Leslie Vernon" (2006), "Maniac Cop" (1988) & "The Collector" (2009). We have to dive into some spooky details to talk about these baddies, so a SPOILER ALERT is in order. Which horror movie villain do YOU think is the least well-known? Let us know in the comments!

When life imitates art, it can get a little scary. For this list, we’ll be looking at horror films and the roles that took a physical, emotional and psychological toll on their actors. Our list includes performances from “Hereditary” (2018), “The Exorcist” (1973), “The Blair Witch Project” (1999), “Psycho” (1960), “Halloween” (1978), and more! Join WatchMojo as we count down our picks for the Top 10 Horror Movie Performances That Messed up Actors.

Scariest part of these horror movie sequels was how awful they were. WatchMojo presents the films that were sequels to horror films that just didn't live up to the originals, or any other good scary movies for that matter. But which awful horror film will take the top spot? Will it be the dreaded Exorcist 2, the universally panned Troll 2, or one of the many unneeded Jaws sequels? Watch to find out!