Junkertown

Junkertown enters the battlefield tapped.
When Junkertown enters the battlefield,
you may search your library for a Junkrat spell,
reveal it, then shuffle your library and put that
card on top of it.
{t}: Add {u} or {r} to your mana pool.
{t}: Add {u}{r} to your mana pool. Spend this
mana only to cast Junkrat spells.