Who said "Everything passes, even the scariest darkness."?

This quote is attributed to Courage the Cowardly Dog.

Everything passes, even the scariest darkness. - Courage the Cowardly Dog

"Everything passes, even the scariest darkness."

Courage the Cowardly Dog Death

"Courage, the cowardly dog."

"What's wrong, Muriel?"

"Oh, the things I do for love."

"Stupid Eustace!"

"Death doesn't scare me anymore."

"Death and I are old friends."

"Welcome to my world."

"Death is just the beginning."