I grew up on an estate and as long as I could remember, there was black gloss paint which seemed to have been thrown and then dried onto the pissy communal stairs. It seemed to make the shape of a hooded, hunched over figure. It was quite terrifying and still now as and adult dream I am walking up this old stairwell, see the spilt paint figure then running for my life as it materialises into a life form.
Any form of fungus and mould or things such as mushrooms growing in woods or sprouting potatoes.
I think I have said it already, but really old fashioned, in particular black and white cartoons. The ones that feature some anthropomorphic cat like character were especially freaky, we occasionally used to have to spend a very boring weekend at our grandparents as children and my nan would shove us, coats and all into the parlour room of their freezing, cold house to watch such creepy old cartoons on VHS to keep us quiet while my grandad watched the pools in the back room.
Their entire house used to scare me as a child. I sometimes used to go through my nans cookbooks to entertain myself, most of them were those really old recipes usually made from scraps in the 40s or 50s. I came across star gazing pie. I dont know why but I was terrified of the photograph of it, it actually made me feel sick too and became unhealthily fixated on the possibly my nan might cook it for us when we were there that I would work myself up into a frenzy over it. It didnt help that whenever I was naughty my mum used it to her advantage to threaten that she will send me over to my nanas and she will cook me a star gazing pie.