Wall of Blossoms

The template for the cantrip wall, and the card that proved a defensive creature could pay for itself. The 0/4 body is doing real work: four toughness is the number that blanks most early aggressive attackers without trading, and the Defender clause is the structural brake on the whole package. A wall that drew a card and also pressured the opponent would have been an absurd rate; locking the body behind Defender is what buys the draw. The replacement-value framing is the whole point. You are not really spending two mana on a creature; you are spending two mana to draw a card and getting a sturdy roadblock as the change. That math is why green's defensive shells leaned on it for so long: it stabilizes the ground and refuels the hand in the same slot, with no downside beyond the inability to attack, which a deck built around it never wanted to do anyway. Its near-identical sibling Wall of Roots took the same plant-wall chassis in a different direction (mana acceleration instead of a card), and the pair together defined what a green defensive two-drop was allowed to look like. The cantrip-on-a-wall idea has been revisited many times since, but rarely with stats this clean for the cost.