The Ur-Dragon is a mythic Legendary Creature — Dragon Avatar card from Secret Lair Drop (SLD), collector number 11. Current market price: — (foil $60.17), TCGplayer market prices via Scryfall.
Eminence — As long as The Ur-Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost {1} less to cast. Flying Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.