I feel like Weeping Angels used to be the most terrifying things around, back in their Blink days. The more they've shown up, the less scary they seem, in my opinion. Still, they are freaking creepy in a way a lot of monsters aren't.

However, like a few people below, I think my vote has to go to either Slender Man or something out of the SCP foundation.

Or, actually, has anyone here read John Dies At The End? Because holy crap that book terrified me.

Weeping Angels, definitely. Because it's really easy for them to sneak up on you -- actually, all they can do is sneak up on you -- and I hate that. Especially in the dark; then I couldn't even see them to pause the sneaking-up. And the invading my brain possibility, and reproducing via my imagination and killing me on the way out... yeah, no. Go away, Moffat, nobody likes youuu... -curls up in a corner-

So, of course, my brain goes to "Hey, y'know what would be hilarious...?" and imagines Maggie being dramatically terrified of the things too. (Which would require a Whoniverse mission... agh, my plate, why do I keep piling things up on it?!)

Yes, a toss up between the Weeping Angels and the Vashta Nerada, although Slenderman gets honorary mention for just being plain damn creepypasta. The fact that no one knows how to defeat Slenderman (whereas we know how to petrify Weeping Angels and more or less deter the Vashta Nerada) just bugs me, I think.

However, I think I would be more afraid of psychological horror things, like if the monster was your own mind sorta stuff.

I'm not really afraid of monsters so much any more. I am immensely bothered by things like demonic possession or alien infestation/mind control like in Animorphs, but I think that's more of a creepy/squicky feeling than outright fear.

When I was younger, I was utterly TERRIFIED of zombies, and was convinced there was an entire empire of skeletons in the pipes beneath the house--with a front door right under my bed, of course.

La Llorona scares me the most. Drowning is the second most terrifying way I can think of to die (second only to burning to death...)

And there is something really horrible about being killed by something that won't even acknowledge you as anyone other than its 'child', especially when it killed its real kids, too...

I agree that the Weeping Angels are terrifying, but I honestly am more scared of the Vashta Nerada. I was always a bit afraid of the dark when I was little, so even now when I've gotten over that fear they really creep me out.

SCP-439.

Scared of eating insects in your sleep? Well, in Soviet Russia this insect eats you when you're asleep.

*Sprays entire house with insecticide*

Hm. The Silence, definitely. I get kinda freaked out when things don't match the way I remember them and I don't know why, so losing your memories of them is kinda my RUN AND HIDE button.

Oh yeah, and then there's the SCP Foundation. They're chalk-full of monsters like that.

Although I can scare myself pretty good, too.

Like these two characters:

"Rogue", who is like the weeping angels in that whenever he attacks or kills something, any cameras or lights, or even one's ability to see, are disabled for the duration of his onslaught. And, what's worse, he horrifically mutilates his victims, but until the lights and cameras and whatnot come back on, it's impossible to know this because his attacks are completely silent. According to the canon I wrote around him, only about four people can withstand his powers - a human scientist with unnatural resilience, a human agent who is really good at dodging, an alien doctor from the same race as Rogue, and ab alien agent, also from the same race as Rogue.

The other character I wrote was based loosely on the story of Faust - and he bears the same name. Basically, Faust is a monster that exists within the self-loathing of others, and uses their hatred and fear as his weapons by which to torment and murder his victims, and that's not even taking into consideration the body-defiling curse he places on his victims that constantly grows worse the more knowledge of their inner selves they obtain, until they become little more than zombies within their own minds. The only survivor from faust's wrath is a boy named Christopher, who escaped from a fire only to watch as his family burned to death from within.

So, yeah. I write some pretty messed up stuff sometimes.

They're the 'perfect' combination of creeping dread and jump scares.