An artifact or creature becomes a 3/3 green Elk creature due to Oko, Thief of Crowns' second ability. What happens to that artifact or creature when it is put into the graveyard? Does it remain a 3/3 green Elk creature? Or does it revert back to it's original state once in the graveyard?
For example, Death's Shadow is turned into a 3/3 green Elk creature. For the purposes of using Unearth, when in the graveyard does it remain as a 3/3 green Elk creature, or does it revert back to being 'Death's Shadow'?