Doldrucrayd, The Barbarian

Flying, Trample, Haste
When you play a dragon onto the battlefield
under your control for the first time this turn,
target opponent puts X cards from the top of
their library into their graveyard, where X is the
creature's converted mana cost.
{x}{2}{w}{b}, {t}: Put a 4/4 black dragon token
creature onto the battlefield. X is that dragon's converted mana cost.