eldritch

I'd never heard this word, even at my advanced age, and with a daughter well-versed in fantasy beings.

Here's the example: 

"He possessed the ability to summon eldritch creatures through a portal to another dimension located in his body."

https://umbrellaacademy.fandom.com/wiki/Ben_Hargreeves_(Netflix)

and the definition:

"Eldritch things are spooky and weird — they make the hairs on the back of your neck stand up."

https://www.vocabulary.com/dictionary/eldritch