Dementors are dark, hooded creatures from the Harry Potter series created by J.K. Rowling. They are known for their ability to suck the happiness and hope from people, leaving them in a state of despair. Dementors are often used as guards for the Azkaban prison, where they feed on the emotions of the inmates. These creatures are described as tall and skeletal, with a chilling presence that can induce fear. They are blind but can sense human emotions, making them formidable opponents. The only known defense against Dementors is the Patronus Charm, which conjures a protective spirit to repel them.