Robot Chicken, Season 5

Snape:
[to Hogwarts students after explaining how to mix a potion] Well, why aren't you writing this down?

Ron:
We usually don't start until you insult Harry.

Snape:
Am I really that predictable? Fine. Uh, Potter, you fool!

Ron:
[after mixing his potion] Well, bottoms up. [drinks it]

Herminone:
How much drops of wolfsbane extract did you use?

Ron:
Uh, three? [his jaw suddenly contracts and his teeth fire off the gums before his head explodes]

Herminone:
Professor Snape, what happened?

Snape:
He used too much wolfsbane extract, it looks like.

Harry:
He used one extra drop! That margin for error is pretty bloody slim!

Herminone:
This spell's supposed to change our eye color. Why would we risk exploding skulls just to change our eye color?

Snape:
Uh... Potter, you fool?