The Swampy Forest

{t}, add {b} and {g}
When this land enters the battlefield create one green and black creature token named
"Dark Tree" with Reach, Defender, and "{t}: Add {b} or {g}.".
Unless you have played a "Walker" subtype creature
or a green and/or spell this turn, then create two
{t}, sacrifice this land, create one green and black creature token named "Dark Tree"
or search your library for one black or green basic
land.