CardName: Stalk-Dewer
Cost: U/GU/GU/G
Type: Enchantment Creature - Spirit
Pow/Tgh: 0/4
Rules Text: Flying; lurk (As long as this creature is untapped, your
opponents can't target it.)
Enchantments and enchanted permanents you control have
"Whenever this becomes tapped for the first time each turn,
produce {C}. Until end of turn, unused mana produced this
way isn't lost."
Flavour Text:
Set/Rarity: [Card Dump] Tahazzar's Designs Rare
Stalk-Dewer
R
Enchantment Creature – Spirit
Flying; lurk (As long as this creature is untapped, your opponents can't target it.) Enchantments and enchanted permanents you control have "Whenever this becomes tapped for the first time each turn, produce . Until end of turn, unused mana produced this way isn't lost."
Lots of (minor?) bending here.
Either way, your deck has to be able to produce

, 

, or some mix of the two.
Other notes: