Forget about skyscraper-sized bosses and zombies — it’s the little things you have to watch out for.

Developers have been sending players out to battle increasingly giant monsters in their games, including the massive, sentient statues in Shadow of the Colossus, the mountain-sized Titan Gaia in God of War III, and whatever the hell that crab monster is at the end of Dead Space: Extraction.

But do you know what all of those enemies have in common? They can’t sneak up on you. They can’t hide, and you definitely don’t have to go looking for them if you suspect they’re around because they’re right over there, blocking the damned sun. And that’s why it’s safe to say that the most terrifying beasties in games are the little ones. Because I’d much rather some huge turtle crush me underneath a hoof the size of a car than have something slither up my leg to do who-knows-what.

Here are some of the most horrifying video game monsters that could absolutely fit under your bed.

Slugs — Another World

You aren’t even a minute into cinematic adventure game Another World before something tries to kill you.

As soon as hero Lester Knight Chaykin materializes on an alien planet after an accident with a particle accelerator and a bolt of lightning, the tentacled beast living in the pool he lands in tries to snatch him up. Get past that giant horror and onto the next screen, and you’ll see some slugs slithering across the ground. But hey, those are just little things, right? Maybe just something to provide ambience and make the world feel like a real, living place.

So maybe you just decide to walk past them, and then this happens:

The big twist is that Lester had actually just transported to Australia.

Above: The big twist is that Lester had actually just transported to Australia, where everything is venomous and wants to kill you.

That’s right — even the smallest thing on this world not only wants to kill you, but it can and will. Immediately. It doesn’t even look like the slugs are going to eat you, unlike every other animal you meet. They just want to stab you with their venom-dripping barbs, slink over your corpse, and go about their day.

Your next time around, you’ll be sure to either step on the slugs or jump over them. And then you’ll reach the next screen and see one just hanging out on the ceiling of the cave, as if poised to drop down the back of your shirt at any second — and that will be the most terrifying moment of your life.

Black Headcrabs — Half-Life 2

Sure, the venomous version of the Half-Life series’ iconic Headcrabs is no smaller than its cousins. But just look at them. Their legs are just a little more spindly, and they have those improbable, wiry hairs sprouting out from odd places. They’re like teenagers who can take your health down to 1 point just by touching you.

And let’s not forget those noises the Black Headcrab makes.

The moment you hear any of those noises, you are on alert — it doesn’t matter what else is in the room. Satan himself could be about to skewer you on a rusty flagpole, and at the slightest chirp from a Black Headcrab, he would drop what he was doing and not come back until he was sure the evil thing was dead.

And you would go help him find it because look at that thing.

Crawlers — Dead Space 2

Most babies are cute. They’re soft, they smell nice, and their tiny hands are small and strong enough to steal anyone’s heart.

And that’s exactly why Dead Space 2 developer Visceral Games chose to use them as the basis for arguably the most terrifying monster in their action-horror sequel. Crawlers aren’t the only Dead Space monsters made of babies — the three-tentacled Lurkers share that origin — but they still mostly look and sound like infants, and therein lies the horror.

The problem with Crawlers isn’t that it’s tough to shoot a newborn or that they’re constantly crying or even that they explode when they get too close to you. It’s that all three of those things are true.

Dogs — Hotline Miami series

It doesn’t matter how elegant, ballet-like, or smooth your murderous infiltrations have been in the Hotline Miami games because any plan you might have must immediately change the moment you see a Dog on patrol.

The diligent Dobermans in this series keep to the walls, tracing them around the room like deadly Roombas. And the moment they see you, they will drop that pattern and just run straight toward you. They are faster than you, and they will kill you with one hit. So will everything else, of course, but something about the methodical way these killer beasts patrol before sprinting toward you as if guided by military lasers and hatred makes it feel more personal. And unlike the gun-toting goons they protect, you have a second to react when a dog sees you, and it gives you some time to really think about what is about to happen.

If you need something to take the terror out of them, however, YouTube is full of videos showcasing the occasionally glitchy A.I. that often has them just walking around in circles:

Honey badgers and snakes — Far Cry 4

We’re finishing up with a double-helping of Nature’s revenge on humanity from the Far Cry series.

Snakes are in both the third and fourth entries, and they’re equally troublesome in both. You’ll just be walking along, looking for bad guys to shoot, and suddenly your heads-up display will disappear, and you’ll have to deal with this fresh nightmare:

The player in this clip even saw the snake before it struck. Usually, you won’t. Maybe you’ll hear one hissing away, and you’ll go looking for it like it’s a Black Headcrab. But most of the time, you won’t even know they’re there until their fangs are in your arm. They don’t do much damage, but they’re scary. And nobody wants fangs in their arm.

Far Cry 4’s honey badgers are a species so hardy that they made the trip up into the Himalayas from their usual, warmer habitats in Sub-Saharan Africa and south India, and nobody even questions them being there. Odds are the badgers sensed that some fighting was happening up in Kyrat, and they wanted a piece of it.

You’ll usually hear them chirruping while they’re eating something much larger than themselves that they probably killed, but that’s your only warning before they come after you with everything their dense, compact frame contains.

Nobody would blame you for using a gun to defend yourself from the little dire weasel, but if you’re hunting them for skins to craft the higher-level holster and quiver, you’re better off going for the double-rewarding “clean kill” with the bow and arrow. Otherwise, you’ll just have to fight more of them.

Honey badgers are the ultimate expression of everything on this list: They are tiny, make a distinct noise, aren’t afraid to run straight at you, and they are very difficult to kill. And you have to prioritize them. Once I was about to storm an outpost full of heavily armed men in Far Cry 4, and I heard the distinctive chitter. And then I decided that my original plans would have to wait because honey badgers are the wild card, and they will ruin everything.