Mommy, Mommy! Are we vampires?
Shut up and drink your soup before it clots!
Listen up, chucklehead! This "joke" is playing on the whole vampire stereotype. The kid asks if they're vampires. The mom is like, "Quit asking dumb questions and eat your soup before it turns into blood pudding!" Get it? It's funny because vampires drink blood, and clotted soup looks kinda like blood. You probably eat soup with a fork, don't you?