Chimeric Sphere

An animated artifact before the template had a name, and a cruder ancestor of the idea that would later define such cards. The whole point is the off-board period: it sits inert as an artifact between combats, immune to the creature removal of its era, then pays two mana to suit up only for the swing it cares about. The two modes are a small but real wrinkle of decision-making baked into the activation: the flying 2/1 for chipping in over ground stalls, or the bigger 3/2 that gives up the air to push through. Crucially, both modes are bought separately and last only until end of turn, so the card never commits to being a creature: it taxes you each combat for the privilege, and that recurring activation is what keeps a colorless, repeatable threat in check. The lineage that follows refines the same idea of a permanent that dodges sorcery-speed creature sweepers by simply not being a creature when the sweeper resolves. This is a mana-hungrier, clumsier version of that template, but the structural insight is already here: separate the body from the permanent, and you separate the threat from the answers built to kill threats.