Svogthos, the Restless Tomb | Magic: The Gathering
Formats Svogthos, the Restless Tomb is Legal in
Official Oracle Text for Svogthos, the Restless Tomb
: Until end of turn, Svogthos, the Restless Tomb becomes a black and green Plant Zombie creature with "This creature's power and toughness are each equal to the number of creature cards in your graveyard." It's still a land.
Official Rulings for Svogthos, the Restless Tomb
8/1/2008 : A noncreature permanent that turns into a creature can attack, and its abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of his or her most recent turn. It doesn't matter how long the permanent has been a creature.
10/1/2009 : Activating the ability that turns it into a creature while it's already a creature will override any effects that set its power and/or toughness to a specific number. However, any effect that raises or lowers power and/or toughness (such as the effect created by Giant Growth, Glorious Anthem, or a +1/+1 counter) will continue to apply.