@JeremyECrawford A silver dragons 'Change Shape' states that they polymorph. Does that last up to an hour like the polymorph spell?
— Leo (@Svenington) January 13, 2017
Change Shape says how long it lasts. The text of a spell is irrelevant to another game effect unless that effect uses the spell. #DnD https://t.co/Jzc32JPPsQ
— Jeremy Crawford (@JeremyECrawford) January 14, 2017