Walking Ballista

A pinger that scales, a removal spell that doesn't expire, and a mana sink all live in the same shell, and the trick is that none of those modes commits you to a fixed size. The cost is the lever: it enters as small as a one-counter Tim or as large as you can afford, and because the counters double as both body and ammunition, every point of toughness is a future point of damage you've stockpiled. That fungibility is what makes the card a combo engine rather than just a flexible creature. Each activation only removes one counter for one damage, so on its own it grinds; pair it with anything that produces or doubles +1/+1 counters faster than it spends them, though, and the loop tips into a one-shot kill, machine-gunning out as many shots as the engine can refill. Its most infamous partner turns lifegain into that fuel, replacing counters as fast as they're spent. The ability is the patient mode, turning excess mana into stored counters across a long game. What ties it together is that the card asks nothing of color: it slots into any deck that can pay for X, which is why its line of work spans point removal, reach against fliers, and dedicated counter-combo. A 0/0 that arrives with nothing printed on its body has rarely been allowed to do this much, and the restraint shown with similar artifact creatures since is part of why.