Mortaron, the World Tortoise

Defender, Reach
Mortaron, the World Tortoise enters the
battlefield with X +1/+1 counters on it where
X is the amount of mana used to cast this spell.
If damage would be dealt to Mortaron, the
World Tortoise while it has a +1/+1 counter
on it, prevent that damage and remove a
+1/+1 counter from it. If you do, search your
library for up to one basic land card, put it onto
the battlefield tapped, then shuffle.