Death-Hood Cobra

Two activated abilities sharing one cost, one body, and one strategic premise: that a 2/2 is worth keeping alive only if it can spend your surplus. Pay two mana and it answers fliers; pay two more in the same turn and it gains deathtouch, becoming a blocker that trades up against anything its size or larger. The body stays small on purpose. This is a mana sink dressed as a defender, the kind of creature that wants you flooded in the late game and hands you something to do with the eighth land. Each activation is a discrete pulse, so the value is not in any permanent buff but in how much green mana you can route through it on a single turn. Deathtouch is the heavier half: a 2/2 with deathtouch makes itself unattractive to attack into, since whatever steps in dies even as the cobra dies too. Reach plus deathtouch together turn it into a deterrent that covers both ground and air, but only one keyword sticks per two mana, so the real question the card poses is which threat to tax this turn (hold up the flier answer, or the deathtouch trade) and whether you can afford both. That choice, repeated every turn you have spare mana, is the entire function of a creature designed to soak attacks while a longer game develops.