*In their bedroom closet, my parents have a walrus skull. Just sort of...hanging out under the coats. Try snooping through your mom's stuff and finding that.
*They use a pair of coffin tables as end tables. The kind you use to put a coffin on for display, which isn't morbid at all.
*There's a horrifying wooden Balinese harpy hanging from the ceiling at the top of the stairs. You don't see it unless you look directly up, which somehow makes it worse.
*In my old bedroom there are doors into the attic. Doors which are about four feet high, and a foot and half wide. Doors that are the perfect size for the evil zombie elves you think might live in the attic. The demon elves that you can hear skittering around at night. They keep you up, making all of their pitter patter noises. Growing up to discover that you can actually hear rats skittering around at night is not any more comforting.
*Another reason my bedroom used to terrify me: it didn't used to have a wall switch for the light. It had a single dangling light bulb hanging from the ceiling in the middle of the room, and you had to walk blindly into the (demon elf infested) dark, reaching for the string to turn it on. Getting light switches installed was a huge bonus.
*Something else that was wrong with my room: when I was in high school (and my light had a switch plate on the wall, which was nice), my bedroom window had a large crack going through it, and my room was consistently 10-15 degrees colder than the rest of the house.
*My room is the biggest bedroom in the house, which somewhat made up for all the other. However, it's now my 16-year-old brother James' room, and the creepy doors have locks on them, the windows have glass(!), so I think he's getting a better deal. Also, while I was always moved out of my room for guests, my parents currently have more bedrooms than in-home children, so they actually have a guest bedroom.
*This isn't actually in my parents' house, but getting back to things that terrified me as a child, on the (perhaps 3 minute) walk through the woods to my Aunt Rebecca's cabin, there's this tree root that looks exactly like a gnarled old zombie man escaping from the Earth. It even looks like that in the daytime as a grownup. Maybe I need to take a picture of it.
My parents actually have a very lovely house in many other ways. Here is a very nice picture of my mommy's kitchen.