The fact of this film is abouta vampire story in Louisianais most likelya tribute to the HBO vampire series True Blood, based on Charlaine Harris's Southern Vampire Mystery books.
This marks the second time that Jim Cummings voices a Scooby-Doo character, not counting the animated series, since 1999 on Scooby-Doo on Zombie Island, where he voiced Jacques, the ferry man.
Stephenie Meyer's Twilight
Velma: Vampires don't sleep in coffins anymore. Nowadays, they sleep in Seatle.
When Velma says this,she's clearly making an allusion to Stephenie Meyer's Twilight saga, which takes place near the city of Seatle.