Genbu

When Genbu enters the battlefield, create X, 1/3 blue and green turtle creature tokens that come
into play tapped, where X is the amount of
mana spent to cast Genbu minus 4.
Turtles you control have "{t}: As long as it's tapped, this creature has Shroud, and gets
-X/+Y, where X equals it's Power and Y equals
it's Toughness".