Mirror Image

Where Clone reaches across the table to copy whatever the opponent has committed, this Shapeshifter looks inward: it can only enter as a copy of a creature you already control. That single restriction flips the entire risk profile of cloning. Clone is reactive, a way to mirror an opposing threat and answer it in kind; limiting the target to your own board makes the effect proactive instead, a redundancy engine that turns your best creature into two of itself. The 0/0 base body is what pays for that restriction: with nothing to copy, or with a choice not to copy, it enters and dies to state-based actions before it does anything, so the card is dead weight on an empty board and only earns its slot once you have a creature worth duplicating. That makes it a payoff rather than an answer, the kind of duplication that rewards a deck already built around a single powerful body or a creature whose enters-the-battlefield trigger you want a second time. The "may" clause is not a safety valve so much as an honest concession that a creature you could copy might carry a downside worse than the copy is worth; in practice you copy almost every time, because the alternative is spending three mana on a creature that hits the graveyard on resolution. It is the inward-facing half of a design space that has otherwise leaned outward since the first Clone appeared, and the narrower aim is precisely what gives it a different job.