Fortunately, there are several free Google Fonts that are perfectly suited for Halloween. But you don't want to taint your design with a cheap and nasty free font either.
However, you don't necessarily want to license an expensive typeface for a one-off occasion. And the right font can make all the difference. It's Halloween season, and whether you're working on a big commercial project or just a poster for a local event, you want your design to convey a sense of suspense, fear, unease or outright horror.