Larten Crepsley (ラーテン・クレプスリー Raaten Kurepusuri) is a vampire who works as a spider-tamer at Cirque du Freak and Darren Shan's guardian. He sees great potential in Darren and bloods him so that he can train him. Though Crepsley has acted cold towards Darren and tests him under a guise of friendliness, he also shows concern for him and regrets changing him after seeing Darren's unhappiness.

It was his idea to bring Darren to the Cirque, as well, to try and better Darren's situation. Despite being a vampire, Crepsley believes that they are not monsters until they kill humans, and refuses to turn someone who is evil into a vampire. He's the protagonist of the The Saga of Larten Crepsley, which shows how he became a vampire.