Blightwidow

The toughness of four is the design choice that makes this an oddity. Almost every green infect creature is built to attack: the poison count it adds is all that matters, and the extra toughness does nothing for a clock measured in counters rather than life. This one inverts the priority. As a 2/4 it survives the ground combat that a 2/2 infect body would lose, and its own combat damage to creatures comes as -1/-1 counters, so a blocked attacker can be shrunk or killed permanently rather than merely traded. Reach is the clause that earns its keep on defense: an infect deck pressing the poison count is poorly equipped to stop an evasive attacker overhead, since chump-blocking with a small ground creature is rarely on offer, and a flier left unanswered ends the game in just a few swings. Phyrexian green of that wave wanted a few durable blockers to hold the air while faster creatures pushed poison, and this fills that gap with a body that bites back. The trick is that infect's defensive math is not what it looks like: this creature takes ordinary damage from non-infect attackers (the kind that clears at end of turn), so a 2/4 wall absorbs more attrition than the rate suggests while still threatening to leave a counter on whatever it blocks.