Shianni, Ranger of the North

Forestwalk
Creatures you control have: "{t}: Add one mana of
any color to your mana pool".
Whenever a source you control taps for mana, add
an extra mana of that color produced.
An arrow sprang out of the wood and nearly hit him,
he said "huh?" The man beside him said, "We are not
in the East anymore"