Magic the Gathering: 10th Edition (Base Set)358-A

*Name: Spawning Pool
Type: Land
Game Text: Spawning Pool comes into play tapped.
T: Add S to your mana pool.
1S: Spawning Pool becomes a 1/1 black Skeleton creature with "S: 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.)
*Source: Front of card