Spawn of Thraxes
The enters-the-battlefield trigger ties its payoff to the one resource a dedicated red deck floods the board with: Mountains, counted when the ability resolves, with the damage pointed at anything you choose. That single design choice rewards exactly the build that wants it least cluttered: not red splashing into other colors, but red as a tribe of basics. A Burning Earth or Valakut shell already keeps a high Mountain count for its own reasons, and this is the creature that converts that count into a second hit on the way down. The math is honest in both directions, which is the discipline here: in a two-color deck the trigger fizzles to a couple of points, and the body alone (seven mana for a 5/5 flier) is a poor rate. The card asks you to pay for it in deckbuilding before it pays you back on the stack. It belongs to the line of red dragons that fold a one-time burst into their arrival, a flying threat that clears a blocker or burns down a planeswalker the turn it lands rather than waiting for a swing. The catch baked into that timing: the burst lives on the trigger, so a counter on the cast leaves you with nothing but seven mana spent. The flying matters less than the trigger; the trigger is the whole reason to run a slow, expensive Dragon over a cheaper one.


