Sporadic laughs spatter this New Zealand mockumentary, which plays less like Spinal Tap meets Twilight than Man Bites Dog eats Vampires Suck. Co-writers/directors Jemaine Clement and Taika Waititi play squabbling nocturnal flatmates whose fellow undeads are as afeared of doing the washing up as they are of garlic and crucifixes. Loosely adapted from a 2005 short, this provokes plenty of giggles but retains the air of an overstretched comedy sketch. While individual gags and cineliterate nods (from Nosferatu to Blade) may have comical bite, there’s not enough meat to sink its feature-length fangs into.