If the Dragon that entered the battlefield is copying something else as the triggered ability resolves, the token will be a copy of whatever that creature is a copy of.
10-06-2022
wotc
Miirym, Sentinel Wyrm's triggered ability copies the printed values of the Dragon that entered the battlefield. It won't copy any counters on that creature or any effects that have changed its power, toughness, types, color, and so on.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.