Cirque du Freak: The Vampire's Assistant (2009)

Teenager Darren Shan is an excellent student and the pride and joy of his perfect middle-class family, but his best friend is the reckless Steve. When they receive a flyer with an advertisement for a freak show, they sneak to the theater to see the attractions. The star attraction is a vampire called Larten Crepsley, who performs with a colorful yet very lethal spider. After the show, Darren tarries to see the spider and overhears Steve unsuccessfully trying to convince Larten to transform him into a vampire. Darren steals Larten's spider, which later bites Steve. In seeking an antidote from Larten, Darren accepts a deal to become his half-vampire assistant.