Leafkin Druid

The 0/3 body is the whole pitch: this is a mana dork built to survive the removal that kills every other mana dork. Where Llanowar Elves and its many descendants die to any one-damage ping and fold under a single blocker, a three-toughness elemental walks under the burn spells that green ramp usually has to play around, and it blocks the early aggressive creatures the deck would otherwise trade with. The conditional second green is the reason it wants a wide board rather than a fast one: alone it is a defensive one-drop-equivalent that taps for a single green, but once four creatures are down it doubles to two, turning a durable blocker into a genuine acceleration piece. That gating is what keeps it out of the pure ramp shells that just want turn-one mana; it belongs in creature-dense green decks that were going to flood the board anyway and can convert that width into extra mana for a payoff. It sits in a small niche of ramp creatures that trade a fragile first-turn play for resilience and scaling later, and the design bet is that a mana source you cannot easily kill and can profitably block with is worth more, over the course of a game, than one that comes down a turn sooner.