Waker of the Wilds

A repeatable mana sink that converts your own land base into threat density, and the way it builds size is the design's whole point. The animated land becomes a 0/0 Elemental, so its entire toughness comes from the X counters you pile on: the counters are not a bonus on top of a creature, they are the only thing keeping it standing. That distinguishes it sharply from the lands-that-attack lineage running back through Mishra's Factory and the Zendikar manlands, which animate to a fixed body on demand. This one scales with whatever you can pour in, but a small activation is a fragile Elemental that any sweeper or toughness-shrink effect erases. The haste closes the window land-animation usually leaves open, letting the surplus mana convert to pressure the same turn instead of telegraphing the swing. And the transformation is permanent: once counters go down, that land is a creature for good, still a mana source but now also a target for creature removal it never had to worry about before. The problem it answers is the classic flood problem. In the late game, drawing a land should not be dead, and here every untapped land is a deferred haymaker waiting on the green double-pip. The 3/3 body is incidental scaffolding; the engine is the ability, and the ability is patient by nature, rewarding the games that go long enough for mana to become the resource you have too much of.