Vampires at a Bar on Halloween

It was Halloween and three vampires went into a saloon and walked up to the bar. "What will you have?" the bartender asked.

"I'll have a glass of blood," the first replied.

"I'll have a glass of blood, too, please," said the second.

"I'll have a glass of plasma," said the third.

"OK, let me get this straight," the bartender said.

"That'll be two bloods and a blood light?"