Egg of the Ur Dragon

Reduce the casting cost of the first creature spell
you cast each turn by {1}
{1},{t}: Add {b},{r}, or {g}.
{b},{r}, {b},{t}: Search your library for an Dragon
card and reveal that card. Shuffle your library,
then put the card on top of it.
"Originally from Jund, it is said to have had a role
in the Conflux that produced Alara. Yet it remains."