"Blue Jay Way", especially the ending chant, which sounds like George Harrison is singing "don't belong", as if he's disappearing from existence altogether.
Please don't be long Please don't you be very long... For I may be asleep.
"Can you take me back where I came from, brother can you take me back?" The song has a very unsettling feel and Paul sounds like he's desperate for help.
Two instances on "A Day in the Life": The deranged string crescendo, which qualifies as a Middle Note Nightmare, and the creepy looping voices at the very, very end of the song, which qualify as a "secret" Last Note Nightmare.
Technically, those looping voices are in a secret track - the "Inner Groove." "A Day in the Life" ends with very faded piano and ambient air conditioning. Which are still Last Note Nightmare.
The Beatles' White Album, potentially made even scarier by reading the lyrics to "Helter Skelter". The album is infamous for being associated with Charles Manson. Ringo's scream of "I got blisters on mah fingers" at the end of "Helter Skelter" also has an unsettling, deranged quality.
Those "electronic seagulls" on "Tomorrow Never Knows". It's a heavily distorted clip of Paul laughing.
It's not just the "seagulls" that are terrifying: the distorted quality of John's voice, occurrences of percussive sounds played backwards, and the sound of tape being looped rapidly through a tape recorder add to this song's freakishness.
John is actually chanting "Shoot me" in the background of the song "Come Together" (according to Bob Spitz's biography) - Paul was supposedly so disturbed by it that he covered up the end of the phrase with a loud cymbal hit, so that it sounds like "shooook!"
"Strawberry Fields Forever", from Lennon's distorted voice to the funereal brass to the backwards cymbals that sound like a shovel digging a grave, not to mention the Last Note Nightmare. The acoustic version in the Anthology is beautiful, though.
"Strawberry Fields Forever" could be deeply disturbing to some. The way it fades out and fades back in at the end...
And the added bonus of John's distorted voice bellowing, "CRANBERRY SAUCE." which could also be interpreted as "I BURIED PAUL." if you subscribe to the Paul Is Dead conspiracy theory.
The version of "Being for the Benefit of Mr. Kite!" on LOVE proceeds as normal for about a minute and a half, right up until the line "And tonight Mr. Kite is topping the bill!", at which point it segues not into the circus music you're expecting, but rather the riff from "I Want You (She's So Heavy)", with various sounds - including the vocals from "Helter Skelter" - laced through it. Also a major case of Mood Whiplash.
The ending of "Long, Long, Long" when everything starts shaking and rattling (achieved by placing an empty bottle on top of a Leslie speaker) and Yoko starts howling into the night.
"Cry Baby Cry", where Lennon sings about "seances in the dark" and a group of children that are always mentioned, but never seen, make one's imagination fear the worst about their fate. Where are they? Are they still alive?
"Run For Your Life," despite its pleasant jangly sound, is about a man threatening to murder his girlfriend if she is unfaithful.
The way "I Want You (She's So Heavy)" just cuts off abruptly.
It is claimed that John had this done intentionally during the final edit. The Beatles: Rock Band does a fine job putting a visual to the increasing volume and distortion before the cutoff.
After listening to the strings fade out on "The End" in Abbey Road, you sit there letting the musical food digest in your brain. All is quiet, until DUNNNN! "Her Majesty", ladies and gentlemen. Of course, this is a subversion, since "Her Majesty" turns out to be a cheerful little ditty.
The Scare Chord is what would have been the end of "Mean Mr. Mustard". That's where "Her Majesty" was originally supposed to go, but Paul thought it didn't sound well in the medley, so it was taken out, though it ended up being tacked on to the end of the album.
"Gnik Nus" sounds spooky thanks to the backmasking.
Then of course there was the "Butcher Cover" which at least was nightmare fuel in its time.
The White Album in general has plenty of odd, dissonant chord progressions, textures and voicings throughout, and a loose, disjointed, ramshackle feel, that create a tense atmosphere through most of the songs. There's also a distant, thin, eerie, often distorted or lo-fi tone to how it was recorded, which doesn't help matters.