Scary Nuns in Horror Films
 

Ghost nuns, demon nuns, killer nuns, wolf nuns, zombie nuns, alien nuns... horror cinema has its own infernal convent, enjoy this guided tour.

Movies I can think of with creepy and/or evil nuns:

Howling IV: The Original Nightmare
The Other Hell (I've never seen it but I know it's about nuns)
original Dawn of the Dead (one of the zombies was a nun)
Sister Act (Whoopi Goldberg gives me nightmares ::EEK!::)

If you've never seen that episode of ARMCHAIR THRILLER..............you don't know scary nuns.

Blues Brothers?

I saw The Nun from 2005 but can't remember it.

https://en.wikipedia.org/wiki/The_Nun_(2005_film)

The Other Hell The is on the frontier of sexual nunsploitation and horror film, it has a good ghost nun and a bad sadistic killer nun

the first ever appearance of Amanda Krueger in a Nightmare on Elm Street part 3 was very unsettling and then in part 5 when she was found behind the Brick wall was creepy as hell.

Oh yeah, I forgot about Freddy Krueger's nun mother in Nightmare on Elm Street.

i forgot about that too.

Was it NMOES 3 that introduced that story? And getting raped in the asylum?

I think so, and it was revealed in the end that she was really a ghost trying to stop her evil son. She appeared in other sequels too after that.