Mysterious Egg

The whole point of this thing is that it isn't one thing yet. A 0/2 body that does nothing on its own is the premium mutate foundation precisely because it's a blank slate: mutate demands a non-Human host, and this Egg exists to be that legal base while contributing nothing you'd mind burying under a stack of mutations. The counter clause turns each mutate trigger into permanent growth, so the body accumulates power and toughness with every layer added, independent of whatever abilities the mutating creatures grant on top. That layering is the design tension: the Egg begins as the least threatening thing on the board and, one trigger at a time, becomes something that can swing for real. It plays a quiet game with information, too. A one-drop that hits the table before anything else does becomes a threat whose eventual size and abilities stay hidden until the pile starts forming, which is exactly where the name earns its keep. Absent mutate it sits there as a defensive body with no upside, and that is by design: this is a build-around enabler, valuable only in a deck that intends to stack creatures on top of it.