Three vampires make a bet to see who is the best at taking blood from their victims. The first one transforms into a bat and flies away. After a couple of minutes he comes back with some blood on his lips. The other two ask him where he got it from.
“See that man over there? That’s where.”
The second vampire transforms himself into a bat and comes back with even more blood than the first one. They ask him where he got it from.
“See that woman over there? That’s who I got it from.”
The third one also transforms himself into a bat. It doesn’t take him too long to come back. His entire body is covered in blood. The other two are amazed and ask him where he got it from.
“See that wall over there?”
They nod.
“Well, I didn’t.”