Spawning Pool | Magic: The Gathering
Formats Spawning Pool is Legal in
Official Oracle Text for Spawning Pool
: Add to your mana pool.
: Spawning Pool becomes a 1/1 black Skeleton creature with ": Regenerate this creature" until end of turn. It's still a land. (If it regenerates, the next time it would be destroyed this turn, it isn't. Instead tap it, remove all damage from it, and remove it from combat.)
Official Rulings for Spawning Pool
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.