A Good Scare

Yikes! Sheldon reacts to the scariest balloon ever in this Big Bang Theory still.
Added:

The Big Bang Theory Season 5 Episode 7 Quotes

Leonard: Oh. Watch out, Sheldon. This little boy Casper is a g-g-g-ghost!
Sheldon: Droll.
Howard: Not as droll as a grown man passed out in a puddle of his own urine.
Leonard: That was pretty droll. With a hint of ammonia.

[reading on wall] "See you in hell Sheldon."
The most frightening thing about that is the missing comma.

Sheldon