Glistener Elf

The clock at its simplest. Infect rewrites the math of aggression: a creature that ordinarily threatens twenty points of life now threatens ten poison counters, and a 1/1 with the keyword represents a single unblocked attack on a path to a kill that doubles down on every pump spell you point at it. Nothing about this body is dangerous on its own; the danger is the multiplier sitting behind it, because poison turns each +X/+X into raw progress toward ten and lets a one-mana attacker carry a one-card-kill if the rest of the hand cooperates. That is the line the whole infect aggro archetype was built around: cheap evasive-by-threat bodies plus a stack of cheap green pump, racing to ten counters before the opponent can profitably block or remove the threat, since blocking a creature whose combat damage arrives as -1/-1 counters is its own punishment. The frailty is the cost of admission. A 1/1 dies to everything, so the deck accepts that any single removal spell ends the plan and compensates by being fast enough that the opponent often does not get a clean window to cast it. Among the green one-drops with the keyword, this is the purest realization of the strategy: no upside text, no toughness to spare, just the smallest possible delivery system for a damage type that counts to ten instead of twenty.