Gravel-Hide Goblin

Four total mana to grow a 2/1 into a 4/3 for one turn is a steep firebreathing rate, and it is priced that way on purpose: the green in the activation cost is a gate, not a bonus. Play this in a mono-red shell and it is a plain 2/1 with a dead line of text, because the ability asks for a color the card itself cannot produce. That gap is the entire structural idea. A guild-common built for a color pair that wants red aggression backed by a green base, it curves out fine on its own and only turns into a real clock once the second color comes online in quantity. It rewards the player who committed to both halves of the guild rather than splashing one card of the off color, and gives nothing to the player hoping to cherry-pick it. This is the humble, quiet work a common can do at the deckbuilding level: nudging a deck toward its intended two-color plan by making the payoff contingent on assembling both mana sources rather than one. The design is deliberately unglamorous, but the tension between a fine base body and a locked-behind-green upside is doing exactly what it was drawn to do.