Hullcarver

The single black mana is the whole equation: this is deathtouch stapled to the cheapest possible body, no downside clause, no drawback text softening the trade. A 1/1 deathtouch drop is a pure combat-math wrench. It blanks the opponent's biggest attacker or blocker, because trading a one-drop for anything they cast is a favorable exchange, and it makes every attack step a question they have to answer before they swing. That role has been filled before by the likes of Typhoid Rats and Vampire Nighthawk's smaller cousins, but stripping the body to bare deathtouch is a design that leans hard on what the keyword does to a board rather than what the creature does on its own. Where it earns its keep beyond the poke-and-trade math is the artifact and Robot Assassin typing, which lets it feed the graveyard-and-artifact synergies that a plain black 1/1 could never touch: it counts for affinity-style engines, sacrifice fodder that leaves an artifact behind, and any effect that cares about the assassin line. The deathtouch is the deterrent; the artifact type is the second job hiding inside a creature whose stat line looks like nothing.