El'Nimhad, Avatar of Wishes

Whenever you cast an instant or sorcery spell,
counter it. Put it onto the battlefield as an X/X
Dream creature where X is it's converted mana
cost instead of putting it into your graveyard. It
enters with "When this creature enters the
battlefield," followed by any additional abilities
it may have. (A spell with "Draw two cards." would
become "When this creature enters the battlefield,
draw two cards.")