(T-shirts and hats. When you reach a certain level you get a mug.

Buffy will let the information settle without interruption because it doesn't sink in for a lot of people right away. She was once in those shoes herself. Space travel? This was going to be a fun world. Although being brought here through a portal must constitute as some sort of space travel, right?)

It depends. Where I'm from vampires don't have reflections and can't be exposed to the sun. Those are some clues. Then there's the tell-all being their "you're dinner" face which goes all sorts of ugly bumpy.