Bloodhunter Bat

A four-point life swing stapled to a 2/2 flyer: that swing is the entire pitch, and the body is mostly a delivery vehicle for it. The drain triggers on a single condition, the creature entering, so there is no loop to assemble and no engine to protect; you pay four mana, you take two off an opponent's clock and put two back on yours, and you keep a relevant evasive blocker afterward. That math is deliberately modest. The two-life increment is the kind of common-rarity drain that fills out a black tribal curve without ever threatening to be a build-around, and the flying body keeps it honest in combat long after the enters trigger has resolved. Cards in this template that want to matter usually find a way to repeat the trigger, through blink or recursion, and the bat does none of that work for you: it is a one-time payment that happens to leave a fair creature behind. As a member of the long line of "small flyer plus minor lifedrain" commons, it sits squarely in the inoffensive middle, designed for slower black decks that count incremental life advantage as a real resource rather than a rounding error.