Dragonlord's Servant

The cost-reducer is the deck's permission slip. Dragon tribal lives or dies on whether the curve is reachable, because the payoff bodies sit at five, six, and seven mana, and casting them on time is the whole project. A 1/3 for two that shaves a generic mana off every Dragon spell does the unglamorous load-bearing work: it turns the seven-drop into a six-drop, the five-drop into a four-drop, and it stacks with itself when you draw more than one. The 1/3 body is the tell that this card is infrastructure, not a threat; the toughness lets it survive long enough to matter on the turns the discount actually counts, and it blocks early aggression while the Dragons assemble behind it. The lineage here is clear: it is the Goblin Electromancer of Dragons, the same flat one-mana-off engine pointed at a creature type instead of an instant-and-sorcery deck. The constraint that keeps it honest is the same one Electromancer accepts: when the discount applies to nothing in your hand, you are holding a vanilla two-drop that does not threaten anything. Build around it correctly and it is the difference between a deck that flops over to a single removal spell and one that lands a fattie a turn ahead of schedule.