Tranquil Marsh

Tranquil Marsh enters the battlefield tapped.
{t}: Add {w} or {b} to your mana pool.
{w}{w}{b}{b}: Choose one:
•Create 3 1/1 black and white Insect creature
tokens with Flying.
•Create a 3/3 black Crocodile with Menace
and Trample.
•Create a 2/2 white Bird with Haste and Flying.