Exuberant Wolfbear

A 4/4 for four in green is honest rate, but the attack trigger points at a design corner most sizing effects avoid: it does not pump the Human, it overwrites the Human's base power and toughness with this creature's, until end of turn. That distinction carries the card. Because it sets base stats rather than adding to them, it works cleanly on a 1/1 token or a small utility Human, and it does not stack the way a temporary bonus would. It also cuts the other way: a Human already larger than 4/4 gets shrunk, so the effect is a replacement, not a buff, and it rewards a board where the Wolfbear is your biggest creature and the Human is your most valuable one. Pair it with a Human carrying a combat-relevant keyword (deathtouch, lifelink, first strike) and you are stapling a 4/4 body onto that ability for a turn, which is where the card stops being a beater and starts asking a question. Green's recurring problem is how to make a midsize, near-vanilla body reach past its own combat step without simply printing another anthem. Setting stats instead of granting them is the quieter, more flexible answer, and it leaves the interesting decision (which Human, and why) on the attacking player's side of the table.