These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Demonic Spiders: the Tarsiers have a nasty habit of dropping on your head. They also take two shots to kill and can more than outmatch your character's turtle walking speed.
Fridge Horror: the last item on your menu list of Animals is Brother. Total: 0
Goddamned Bats: Moles, which will assault you after your first step into the cupboard dimension.
That One Level: the electric underwater maze, which has you navigating through a room full of sharp turns in water without touching any walls. You have all the elbow room of a thimble. Black tentacled creatures appear in random places (sometimes overlapping you) as a visual distraction, and, to make it worse, the last save point is a few rooms back, so when you die (which will be often), you repeatedly have to traverse this same area.
There's no immediate save point after the maze either. In fact, you have to navigate an ocean filled with enemies and face a boss without dying before that happens. Good luck if you left the maze with only two hit points.
And then you have to backtrack and go through the maze again.