River Heralds' Boon

The clever part is the second clause is conditional, not wasted. Most +1/+1 counter instants commit fully to one target; this one puts a counter on any creature and, if you happen to control or face a Merfolk worth growing, throws a second counter on top. The "up to one" wording means the Merfolk half never strands the card: in a deck with no fish, it functions as a plain pump-and-pad combat trick, and in a Merfolk-heavy board it doubles its rate for free. That flexibility keeps it playable outside its tribe rather than bricking when the fish do not show up. The counters matter beyond combat math, too: because they are permanent +1/+1 counters rather than a temporary buff, they survive past end of turn and feed anything that cares about counters being present. Played at instant speed, it does the usual combat-trick work of ambushing an attacker or saving a blocker, but the lingering body growth is the longer-term return. It is a modest card by design, built to reward boards that lean into a single creature type without punishing decks that do not, and the asymmetry of "one guaranteed, one rider" is a tidy way to make a tribal trick that still reads as playable when the tribe is thin.