Pheres-Band Brawler

Fight-on-a-body is green's oldest workaround for a color that refuses to print clean removal, and this is the honest, unglamorous version of that bargain. The 4/4 sets both terms of the exchange: four power kills anything with four or less toughness on arrival, and four toughness dictates what it survives, so it walks away from any target whose power is three or less and dies to anything hitting for four or more. The "up to one" clause is the quiet mercy that separates this from a bare, mandatory fight trigger. The ability still goes on the stack every time the creature enters; choosing zero targets is simply a legal option, so it can resolve doing nothing rather than dragging you into a fight you don't want. The real bind is a board where the only legal target is a 5/5 deathtouch you have no interest in trading into, and "up to one" lets the Brawler decline that fight and land as a plain beater, choosing its spots rather than being marched into a bad exchange the board dictates. Six mana for a 4/4 that mops up one small-to-midsize blocker sits near the top of a green curve, and the fight resolves once on entry rather than as a repeatable engine, so the value is strictly one-and-done. It is a workmanlike answer-plus-threat, rounding out a green creature suite without asking anything of the deck around it.