Running skeleton
 Several humanoid figures, which are revealed to be a group of zombies
 Lights or torches go out from far away towards you like woosh woosh WOOSH
 You don't see anything but you hear something. It's on the ceiling creeping closer.
 This one requires a door or corner or elevator- just a shit ton of blood sloshing towards you.
 You can't see them with your eyes; dark spooky ghouls which you can only see in mirrors.
 Generic looking ghost person floating, gives dire warning, fades away with echoing moans.
 Creaky wheelchair is on its side, wheel spinning for no reason.
 Ball bounces down hallway towards you, spooky kid laugh eminent.
 Little puppet on a tricycle rolls up to you, clearly just a machine. Still a little spooky.
 Bunch of mannequins. Seem to move when you're not watching.
 B A T S
 Giant hand or grasping tentacle, slams down, then slinks away into darkness.
 It's like snow that falls from the roof. You taste it but it's actually ash.
 Ghostly figure of a big face that warbles laughter at you. Probably asks you riddles.
 Arrows. It's just orcs. Not supernatural horror at all, just a good ambush.
 Some kind of pipe or something shaking along the wall. When you reach the end of it- just a blood handprint is all that's left.
 Bloody normal person who is really screwed up. They fall in your arms and say something ominous and then die.
 You see a man a coat and broad-brimmed hat moving towards you from the darkness, the hat pointed downwards to hide the man's face. Of course there is no man, when you get close enough to see he has no legs it falls down and you realize it's just some random clothes that were levitating.