Maybe just don't make too many wishes? And you'll be okay? I-I don't know.

[He pauses as he rubs at the back of his neck, still trying to remember the exact wording of his fortune, but failing. Did it rhyme? Oh well, it's not like it really matters.]

Maybe they meant the normal blood-lusting monster that makes us all vampires. But I suppose it could be some other kind of monster? It could be a metaphor for... something...