Drawing a piece of equipment when you don’t have any creatures on board can sometimes be a bit of a letdown, as while you can get the equipment on the board, it can’t really help you out right away. Living Weapon from Scars of Mirrodin Block solves that potential problem.
When you cast an Equipment with Living Weapon, as it enters the battlefield you create a 0/0 Phyrexian Germ token and attach that equipment to it. This happens all at once, so the Germ will always get the stat boost that the equipment grants as soon as it exists.
And…yeah, that’s really it. The entire point of Living Weapon is that it’s equipment that equips itself. It does also have a normal Equip cost, so you can move it around onto your other creatures. But if there’s nothing else buffing the Toughness of the Germ, it will immediately die.
Living Weapon was a decently popular mechanic, but is flavored very specifically to Phyrexians. While the mechanic itself has only ever come back in special sets, the idea has come back slightly tweaked a couple of times. In Core Set 2020, there was a small cycle of Equipment that made their own creatures, but not Germs. Later, in Kaldheim, another cycle of equipment came along that you could pay extra to have make a token and enter attached to that token – again, no Germs. Most recently, Kamigawa: Neon Dynasty introduced the Reconfigure mechanic, with literal equipment creatures.
So while living Weapon itself may return in a Phyrexian-oriented set, its legacy persists in other forms to this day. If you want it to be part of your collection, head over to cardkingdom.com!