Skystinger

Reach has always been green's grounded answer to flying: a body that stays on the dirt but stretches up to catch what the color cannot otherwise chase. Most reach creatures are content to trade or stall. This one is built to punish. The +5/+0 trigger fires specifically on blocking a flier, turning a plain 3/3 into an 8/3 that outmuscles almost anything on wings. Note where the math lands: at 3 toughness the creature still dies to any flier with 3 or more power, so this is a trade-up, not a survivable wall. It eats the attacker and often dies doing it, spending itself to remove a bigger, more expensive threat. The design constraint is precise and worth reading closely: the bonus is tied to blocking, not attacking or dealing damage, so the card is reactive rather than proactive. It sits back, dares an aerial attacker to commit, and taxes the swing. That makes it a deterrent as much as a blocker; a flier staring down this creature is frequently better off grounded. The narrower wrinkle is that the bonus keys on the flying keyword specifically. A 3/3 body still blocks a trampler or a double-blocked menace creature, it just does so without the swing, meaning it can chump but not favorably trade against ground evasion. Against the exact thing it was designed to stop, though, the exchange is lopsided enough that most aerial attackers do not survive the encounter.