Dementors are dark creatures that used to be guards in Azkaban until book 6. They were controlled by the ministry of magic, and the death eaters. The exptro patronus is the spell that repells them.

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.