Who said "Ash and bone is all that remains."?

This quote is attributed to Drogon.

Ash and bone is all that remains. - Drogon

"Ash and bone is all that remains."

Drogon Death

"I am fire. I am death."

"Dracarys."

"A dragon is not a slave."

"I will burn them all."

"Death doesn't scare me anymore."

"Death and I are old friends."

"Welcome to my world."

"Death is just the beginning."