@JeremyECrawford Hi, I recently DMed for a WotC sponsored video series with Viva La Dirt League and in the newest episode I allowed Hold Person to work on a mummy and a skeleton. The comments are blowing up in debate over whether it should work or not. Does nothing hold undead?
— Robert Hartley (@RobHartley007) August 12, 2019
Hold person works only on creatures that have the humanoid creature type. Undead is a different type.
Hold monster works on any type of creature, except undead.
— Jeremy Crawford (@JeremyECrawford) August 13, 2019