Gryaash, Swarmer of Graves

Flying, Trample, Persist
When Gryaash swarmer of graves enters the battlefield Exile a card from your graveyard then put a 4/4 Zombie Dragon Token into play
When ever Gryaash, Swarmer of Graves die and returns with persist. Make a copy of Gryaash Swarmer of Graves expect it loses legendary and is a 4/4