@JeremyECrawford can a monster take legendary actions while surprised?

— Kenichi Haramoto (@kenichiharamoto) February 15, 2017

Can a monster take a legendary action while surprised? The answer is no, as clarified in the MM errata: https://t.co/sqSsx1dMrp #DnD https://t.co/xWAuSwkKca

— Jeremy Crawford (@JeremyECrawford) February 16, 2017