Rotcrown Ghoul

Mill as a death trigger is the wrinkle worth pausing on here: the five-card chunk fires only when the body dies, which turns the creature into a clock that an opponent has to choose between leaving on the board and removing. Killing it advances their own mill (or yours, since the trigger targets any player); blocking it advances their mill; ignoring a 3/3 lets it chip away. The deck this was built for is the slow self-mill or opponent-mill strategy that wants its threats to pay out on the way to the graveyard rather than demanding immediate value, and a five-mana 3/3 with a deferred payload is squarely an early-era take on that idea, back when mill was a fringe wincon rather than an archetype with a reliable engine behind it. The catch is the math: five cards is not a fast clock, and the trigger only happens once, so the card asks a mill deck to field a whole team of these incremental contributors rather than lean on any single one. It is fodder for a grind, not a finisher, and that is exactly the niche it was cut to fill.