Grassy Crater enters the battlefield tapped.
: Add or to your mana pool.
Put Grassy Crater on top of your library: Add to your mana pool.
: Grassy Crater becomes a 2/2 green Snake creature until end of turn. It's still a land.
: Add 
or 
to your mana pool.
to your mana pool. 
: Grassy Crater becomes a 2/2 green Snake creature until end of turn. It's still a land.
