Enchantment, 1GG (3)
Rare
Whenever a creature you control attacks, put a charge counter on Druids' Repository.
Remove a charge counter from Druids' Repository: Add one mana of any color to your mana pool.
Illus. Daarken

5/1/2012: The first ability of Druids' Repository will trigger once for each creature you control that attacks.
5/1/2012: You can activate the second ability of Druids' Repository multiple times in the same turn. It's a mana ability, doesn't use the stack, and can't be responded to.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Standard (Type 2)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern