Virulent Emissary
A one-drop that stitches together two jobs green rarely holds in the same slot: a deterrent and a lifegain engine. Deathtouch on a 1/1 turns the body into a tax on every attacker, since trading a real creature into it is a losing exchange, but the second line carries the real design weight. Every other creature entering under your control drips a point of life, which reframes the card from a defensive speed bump into the payoff for a go-wide board. Tokens, dorks, recursion loops, reanimation flickers: each trigger is another point, and the count scales with how fast you can flood the board rather than how expensive the creatures are. That coupling is deliberate. The deathtouch keeps the emissary relevant when you are behind (it blocks up indefinitely), while the lifegain rewards you for being ahead, so the card straddles the aggro-attrition line that green-based creature swarms usually have to choose between. It asks for a deck that plays lots of small bodies and enters them in bunches, then repays that construction with a passive drain-in-reverse: not enough to build a combo around, but enough to blunt an opposing clock while your board does the actual killing.

