Mana Echoes

Enchantment, 2RR (4)
Whenever a creature enters the battlefield, you may add {1} to your mana pool for each creature you control that shares a creature type with it.¹
When the ground is saturated with mana, even the lightest footstep can bring it to the surface.
Illus. Christopher Moeller

Gatherer Card Rulings [Nov 2009]

• 10/4/2004: You either get zero mana or all the mana. You can't choose an amount in between.
• 10/4/2004: You do get to count the creature itself, you even get one mana if it is the only creature you have on the battlefield (assuming it has at least one creature type).

Format Legality	Legal in Vintage, Legacy, MTGO Classic Banned in Extended, Standard
Printings (1/6)	Onslaught (Rare)