He was trying to conjure up a succubus." It should be impossible to leer when all you've got is a beak, but the parrot managed it. "That's a female demon what comes in the night and makes mad passionate wossn-"
"I've heard of them," said Rincewind. "Bloody dangerous things."
The parrot put its head on one side. "It never worked. All he ever got was a neuralger."
"What's that?"
"It's a demon that comes and has a headache at you.

Author: Terry Pratchett