Kessig Recluse

Reach and deathtouch on one body is the design that lets a small green creature tax the entire battlefield. Reach answers the evasion green normally cannot interact with; deathtouch removes the need to win the toughness arms race, since any block, ground or air, kills whatever it touches. The asymmetry is the point: a 2/3 deters a creature of any size, because attacking with a dragon means trading the dragon for a four-mana common. That the trade is mutual is what keeps the deterrent honest. Without first strike, the Spider dies in the exchange, so it is not a permanent wall that sits there policing the skies. It is a single insurance payout, a threat that an opponent's biggest attacker eats one of your creatures the moment it swings. The Spider creature type is where this combination keeps landing, because the flavor of a web that snares anything large does the rules work for free. What balances it is the body. A 2/3 trades into nothing profitably on offense and applies no pressure to a life total, so the card is purely defensive: it blocks once, kills once, and is gone, having converted four mana into a removal spell that fires on the opponent's terms rather than yours. It is a clean specimen of the deathtouch-blocker template green has refined many times over, priced so the insurance never threatens to win the game on its own.