Lifeless Swamp

{t}: Add {b} to your Mana Pool.
{b}{t}: Bury Target Attacking Creature.
{b}{b}: Lifeless Swamp becomes an
Enchantment Creature that Reads:
When this Creature Untaps, bury it and
return Lifeless Swamp to its Owner's Hand.
"In Ethiopia there's a place with negative
pH values. Negative!" -Amun-Ra-Gaia