Who said "Mortality is the only thing that truly scares me."?

This quote is attributed to Mr. Burns.

Mortality is the only thing that truly scares me. - Mr. Burns

"Mortality is the only thing that truly scares me."

Mr. Burns Death

"Release the hounds!"

"I'm trying to be a better man, but it's exhausting."

"Money can be exchanged for goods and services."

"Smithers, release the robotic Richard Simmons!"

"Death doesn't scare me anymore."

"Death and I are old friends."

"Welcome to my world."

"Death is just the beginning."