Heyo, I'm DMing and need help

Heyo, I'm DMing and need help
So Veeky Forums my setting's "demons" are critters that come through the barrier that separates imagination and reality (often through the head of whoever imagined it)

Give me some ideas for (literally) nightmarish creatures to throw at the party.

Shameless self bump
toss me some ideas
(Holds out cup and shakes it)

Not all of them should be unpleasant or hostile. Think just surreal Yume Nikki shit for at least some of them.

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Try some universal horrors
>A monster that hides under the bed and drags people under to attack them. This monster can also teleport between different under the bed spaces
>A writhing mass of cockroaches, centipedes, scorpions, beetles and other biting insects that always seems to stay together and regens health
>OPs image of the dead rotting corpse that borrows from our fear of death
>A creature that appears in any deep water that manifests itself as a massive toothed maw that comes out of the deep

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