Who said "Gratitude is what the defeated whisper to the victor."?

This quote is attributed to Mr. Freeze.

Gratitude is what the defeated whisper to the victor. - Mr. Freeze

"Gratitude is what the defeated whisper to the victor."

Mr. Freeze Gratitude

"I'm not a human anymore. I'm something... colder."

"My wife, Nora... she's all that matters to me."

"Vengeance is a cold dish best served frozen."

"The cold never bothered me anyway."

"Gratitude makes life richer."

"A grateful heart is a happy heart."

"Respect those who came before us."

"Life's greatest treasures are the people we love"