Green Stadium enters the battlefield tapped unless you pay .
: Add or to your mana pool.
Sacrifice Green Stadium: Add or to your mana pool.
: Green Stadium becomes a 2/2 green Elf creature until end of turn. It's still a land.
.
: Add or 
to your mana pool. or to your mana pool.
: Green Stadium becomes a 2/2 green Elf creature until end of turn. It's still a land.
