Leonardo da Vinci

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

Except for the listed exceptions, the token copies exactly what was printed on the discarded card and nothing else.

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

The token is a Thopter artifact creature in addition to its other types. Its power and toughness are 0/2, and it has flying. These are copiable values of the token that other effects may copy.

The value of X is determined only as Leonardo’s first ability resolves. Once that happens, the value of X won’t change later in the turn even if the number of cards in your hand changes.