Yeva, Nature's Herald

Oracle Text

Flash (You may cast this spell any time you could cast an instant.)

You may cast green creature spells as though they had flash.

Card Rulings

7/1/2012 You still pay the costs for green creature cards you cast.
7/1/2012 Yeva’s ability applies to green creature cards in any zone, provided something is allowing you to cast them. For example, if the top card of your library is a green creature card and you control Garruk’s Horde, you can cast that card as though it had flash.