(: Add or to your mana pool.)
When Howltooth Karst enters the battlefield, sacrifice it unless you pay 1 life.
: Howltooth Karst becomes a 2/1 black and green Rat creature until end of turn. It's still a land.
: Add 
or 
to your mana pool.): Howltooth Karst becomes a 2/1 black and green Rat creature until end of turn. It's still a land.
