The vampire bat, with its big eyes and razor sharp incisors, is one of neotropic’s most iconic animals. A protein from its saliva, Draculin, acts as an anticoagulant and may one day be used as treatment for blood clots that starve the brain of oxygen during a stroke. With a vampire genome, we are now in an excellent position to understand and separate fact and fantasy in the evolution of vampires by sequencing and analyzing vampire RNA during development.