Restless Bones

Evasion-granting on a stick was a recurring black uncommon idea back when landwalk still passed for a payoff, and this is one of its odder executions: the activated ability hands swampwalk to any creature, not just to itself, turning the Skeleton into a repeatable enabler rather than an unblockable threat in its own right. The gift only does anything when the opponent controls a Swamp, so the whole package is a mono-black mirror-breaker. In a stalled black-on-black board where creatures can trade and block each other normally, swampwalk is precisely the thing that lets one attacker slip through untouched, and the Skeleton can hand that out turn after turn. That narrowness is the tax on a four-mana activation that would otherwise read as a generic Rogue's Passage on legs. The regeneration is the part doing the quiet structural work: a 1/1 that can pay to shrug off destruction and combat death stays on the battlefield long enough to keep activating, which is the only reason the swampwalk engine is worth building toward at all. Without it the body dies the first time it blocks or eats a burn spell, and the expensive ability never gets a second use. Taken together it is a self-protecting tap-ability creature whose payoff is conditional on the opponent's land base, a design that reads more like a kitchen-table puzzle than a constructed tool: durable, repeatable, and pointed at exactly one kind of board state.