Pazuzu from The Exorcist surely. The movie was banned until I was an adult, but even at 22 it really scared me
The Wolfman is rubbish now, but as a kid the werewolf freaked me out more than anything.
The witch from HR Pufnstuff. This was on here in Scotland when I was around 3 and she featured in the first nightmare I can remember having, where she asked me to go to the shops to get her something. Not that scary, I know, but I remember crying about it when I woke up.
Death in the Devil Rides Out. Again, not that scary now, but I remember thinking this was the best horror movie I’d ever seen when I was 10 and a rare hero roll for Christopher Lee, whom I always loved. That movie really built up brilliantly and this was the big horror orgasm at the end.
*Honourable mention: The kid scratching the window in Salem’s Lot and Henry from Henry: Portrait of a Serial Killer, which was such a brilliant performance I had to go and see Little Man Tate right after it to get it out of my head.
I always liked Dracula and Frankenstein pics, but the latter never scared me even as a kid. I got to stay up late every Friday night for the STV horror double bill (usually Hammer or Amicus) and Saturday was a more classic Universal horror double-bill, like Dracula or Creature from the Black Lagoon. No version of these characters ever scared me as far as I recall, though I liked them a lot. Same goes for the 80s slasher characters. I loved them as movies, but never felt that dread the above gave me.