Grass-Castle enters the battlefield tapped.
: Add or to your mana pool.
Put Grass-Castle on top of your library: Add to your mana pool.
: Grass-Castle becomes a 0/4 green and white Stag creature with defender until end of turn. It's still a land.
: Add 
or 
to your mana pool.
to your mana pool. : Grass-Castle becomes a 0/4 green and white Stag creature with defender until end of turn. It's still a land.
