Ferrovore

Feed it metal and it swings for the fences: every spare artifact you can pay a red mana to crack becomes another +3/+0, and the pump stacks as many times as the supply holds out. That dependence is the whole design. The activation asks for red mana on top of the sacrifice, so each pump is a deliberate cost rather than a free dump of your board, and a defender has to recalculate the attack every time a permanent leaves play. Drown the table in cheap, disposable artifacts (tokens, busted Equipment, tapped-out mana rocks) and a small beater becomes a reach engine that cashes the whole pile in during one alpha strike. Starve it and the threat collapses to an effectively plain 2/2, its floor sitting exactly where the metal runs out. The lineage is the familiar red sacrifice-hungry attacker that converts board presence into damage, but where most of those eat creatures, this one is calibrated to a build that treats artifacts as ammunition instead of assets: it wants you overflowing with fodder and willing to spend it all in a single swing, leaving nothing behind.