True Polymorph

True Polymorph causes the first target permanent to copy the printed values of the second target permanent, including any copy and mutate effects that have been applied to it. It won't copy counters on that permanent or effects that have changed its power, toughness, types, color, and so on.

If either target is an illegal target for True Polymorph as it resolves, the spell will do nothing.

If the first target becomes a creature the same turn it entered the battlefield, you can't attack with it or use any of its {T} abilities unless it has haste.