Fountain Grass

Defender
Red mana doesn't empty from your mana pool.
At the end of your turn, for each red mana in
your mana pool, add another red mana to your
mana pool.
At the beginning of your upkeep, deal 1 damage
to all legal targets for each red mana in your
mana pool. If Fountain Grass would die this way,
exile it and return it to the battlefield at the the beginning of the next upkeep.