See Double

If the copied creature has {X} in its mana cost, X is 0.

If the copied creature is a token, the token that’s created copies the original characteristics of that token as stated by the effect that created that token.

If the spell that’s copied has an X whose value was determined as it was cast, the copy will have the same value of X.

You may choose both modes if any opponent has eight or more cards in their graveyard, not necessarily all of them.

If the spell has damage divided as it was cast, the division can’t be changed (although the targets receiving that damage still can). The same is true of spells that distribute counters.

Any enters-the-battlefield abilities of the copied creature will trigger when the token enters the battlefield. Any “as [this creature] enters the battlefield” or “[this creature] enters the battlefield with” abilities of the copied creature will also work.

You can’t choose to pay any alternative or additional costs for the copy of the spell. However, effects based on any alternative or additional costs that were paid for the original spell are copied as though those same costs were paid for the copy.

The copy will have the same targets as the spell it’s copying unless you choose new ones. You may change any number of the targets, including all of them or none of them. If, for one of the targets, you can’t choose a new legal target, then it remains unchanged (even if the current target is illegal).

A copy of a spell is created on the stack, so it’s not “cast.” Abilities that trigger when a player casts a spell won’t trigger.

If you copy a spell, you control the copy. It will resolve before the original spell does.