The Lord Holds for Ransom

Enchant creature
You control enchanted creature, it loses all
abilities and has base power and toughness 0/3.
At the beginning of your upkeep, the player that
owns enchanted creature may pay it's X, where X
is enchanted creature's mana cost. If he or she
does, sacrifice this enchantment, you get X gold artifact tokens with "Sacrifice this artifact:
Add one mana of any color to your mana pool"