Marang River Skeleton

The regenerating skeleton is one of black's oldest templates: a body that refuses to die in combat for a single mana, a line that runs back to Drudge Skeletons. What this design grafts onto that template is a face-down disguise. Cast anonymously as a 2/2 for three, the card flips up once for its megamorph cost and gains a permanent +1/+1 counter, upgrading the printed 1/1 into a 2/2 that keeps its regeneration ability. That flip is the split-second surprise: an opponent commits blocks or attacks against a generic morph, and the counter arrives alongside a body that can now shrug off destruction, blowing up the combat math they had planned for. After that, the body settles into pure attrition. Regeneration is not a comeback from the graveyard but a shield paid for in black mana: activate the ability and the next lethal event that turn is prevented, the creature tapped and removed from combat instead of destroyed. A single open black source resets that shield every turn, so an opponent has to overcommit removal or blockers to actually clear it. The friction is real: the base 1/1 does nothing if it never flips, the megamorph cost is not trivial, and holding up to keep the shield live competes with everything else the mana wants to do. This is grindy, ground-stall work, a wall that trades up and stands back up as long as a black source stays untapped.