Who said "Your efforts are beneath even my low expectations."?

This quote is attributed to Severus Snape.

Your efforts are beneath even my low expectations. - Severus Snape

"Your efforts are beneath even my low expectations."

Severus Snape

"It is our choices that show what we truly are, far more than our abilities."

"Dunderheads. All of you. Particularly you, Potter."

"I can teach you how to bottle fame, brew glory, even put a stopper in death."

"One sip of this potion would make a man invincible."