Writhing Necromass

In Commander, Writhing Necromass belongs in graveyard-heavy black decks that naturally accumulate instants and sorceries — spellslinger commanders and self-mill strategies can drop this for a single black mana as early as turn four or five. In Pauper it is a legitimate threat; the format's graveyard-filling cantrips and cheap removal make the cost reduction easy to hit, and a 7/6 menace at common is exceptional rate. Modern and Pioneer have faster clocks and more efficient threats at the same price point, so Writhing Necromass sits on the fringe there — playable in dedicated graveyard brews but not a format staple. Legacy and Vintage move too quickly for a creature that needs setup, and the non-rotating formats offer strictly stronger payoffs for the same archetype.