Basin of Ixalan

{t}: Add one mana of any color to your mana pool
{t}, Pay 1 life: Search your library for up to three basic lands and put them onto the battlefield. Then, shuffle your library.
{w}{u}{b}{r}{g}: Put a 10/10 gold Elemental creature token with vigilance onto the battlefield.
{w}{u}{b}{r}{g}, Pay 10 life: This land becomes a 20/20 Plane creature token with trample and haste until end of turn. Sacrifice it at the beginning of the next end step.
That is Ixalan herself.