Bart and Lisa screaming gif
Adam Rifkin stashed this in Simpsons!
Bart and Lisa tongues out gfy: http://gfycat.com/ImaginarySafeAmericankestrel
Thank you ChemicalOle for making this gif: http://gfycat.com/ChemicalOle/simpsons
Immediately preceding this:
Aaaaaahhhh! Plug it in! Plug it in!
The rock tumbler or the TV?
The TV! The TV!
From "Homer Goes to College": http://simpsons.wikia.com/wiki/Homer_Goes_to_College/Quotes
When the nerds unplug the TV displaying Itchy and Scratchy to plug in their rock tumbler: