Bilbo Baggins

When Bilbo enters the battlefield, draw a card.
If the drawn card is an artifact, you may cast it
this turn without paying its mana cost.
{2}, {t}: Exile target artifact. If it's an artifact you
control, add X amount of {c} to your mana pool,
where X is the exiled artifact's mana cost. Return
the exiled artifact to the battlefield under your
control at the beginning of your end step.