Marang River Prowler

Plenty of creatures dodge blockers; this one refuses to stay in the graveyard. The recursion clause is the whole identity, and its gate is deliberately awkward: you can recast it only while you control a black or green permanent, one of them an ally to blue and one an enemy, so the card asks you to reach for one of those colors rather than stay purely mono-blue. In a mono-blue shell it dies once and stays dead. Give it a wedge to live in and it becomes a renewable clock. The recursion is not free (you pay again each time), which is the lever that keeps it fair: what the clause waives is the graveyard tax, not the mana, so it grinds out chip damage at a payable pace instead of flooding the board for nothing. The can't-block, can't-be-blocked line does double duty, guaranteeing an aggressive body that never trades in combat and never clogs a lane. Note the one thing the recursion cannot survive: the card returns only from the graveyard, so feeding it to a delve spell or any exile-based effect ends the loop for good. That tension is the design's real spine. It wants to be killed and bought back, spent and rebuilt, but the moment it leaves for exile it is gone. The reward is reserved for decks that have already paid the deckbuilding cost of being black or green rather than merely dipping a toe.