"Break off in case of sparkly vampires" - I think this would be even more effective without the "Sparkly" part. But In all seriousness this sign is racist against vampires. A hate sign is what this is!
Great mason jar idea - try to make this on your own! - you could really use any old jar - soak the label off with oxyclean and warm water first. You could do Christmas jars, too. white for snowman, green tree with sequins glued on as lights.