Ebony Treefolk

The pitch here is that black and green can share a deck, made by a creature with a mana sink built sideways: instead of giving a green firebreather the usual toughness pump or evasion, the activation grows the body symmetrically, turning untapped enemy-color lands into late-game combat math. A 3/3 for three is a fair floor, and the ability reads as a place to dump excess mana into a clock that scales when there is nothing better to do. The problem is the rate of the pump itself. Two mana for a one-turn, +1/+1 swing is the kind of math that loses badly to almost any contemporary firebreather, which buys more size per activation, and Treefolk had no tribal payoff infrastructure to lean on at the time. What it represents is the workhorse end of an early enemy-color experiment, when the design goal was less about printing powerful gold cards than about proving the two-color pair had a functional curve. It is a creature whose entire reason for existing is to show that a black-green board has something to do with leftover mana, a slow deck's way to push the last few points, asking for nothing clever in return.