(: Add or to your mana pool.)
Fetid Ruins enters the battlefield tapped.
: Fetid Ruins becomes a 2/1 black and blue Specter Rat creature until end of turn. It's still a land.
: Add 
or 
to your mana pool.): Fetid Ruins becomes a 2/1 black and blue Specter Rat creature until end of turn. It's still a land.
