Life-Siphoning Elemental

Reach, lifelink
When Life-Siphoning Elemental enters the battlefield, place a -1/-1 counter on target
creature. Add one mana of any color to your
mana pool.
{b/g}{t} Place a -1/-1 counter on target creature.
Create a treasure token with "Sacrifice this
artifact: Add one mana of any color."