Goblin Warchief

Two effects that turn a pile of one-drops into a deck. The cost reduction makes the curve fold in on itself: a tribe already built on cheap, redundant bodies gets to deploy a turn earlier and refill faster, and the haste line means every Goblin that lands attacks the moment it arrives. That second clause is what made this the engine card rather than a payoff card. Goblin Lackey and Goblin Recruiter could find the gas; this is what made the gas lethal on arrival, collapsing the gap between a board state and the kill that other aggressive tribes have to wait a turn for. The discipline is in the body: a 2/2 for three that dies to everything, so the reductions and haste only matter while it lives, and the deck has to commit to flooding the board around it rather than leaning on it. Goblin tribal in older formats is essentially the question of how many copies of this and Goblin Chieftain you can stack, because the haste does not double up but the cost reduction does, and a second copy turns a fair curve into a free one. It sits at the structural center of one of the oldest functioning tribal aggro decks in the game: not the threat, not the toolbox, but the converter that makes the whole pile move faster than its mana value suggests.