Bramble Creeper

The math is the whole pitch: a 0/3 that swings for five the moment it turns sideways, with the entire identity living in the attack trigger. The drawback is priced into the rate rather than tacked on as a downside clause: you pay full freight for the body up front and only collect the +5/+0 once the creature is committed to the red zone. That makes it dead weight on a stalled board (a five-mana 0/3 that lands into a clog does nothing) and live whenever you already have the tempo to keep attacking. The wrinkle is the asymmetry of the threat. A defender has to respect five power every time it swings, but three toughness is the toll: the buff lasts until end of turn, so the creature stays a 5/3 through your own post-combat main phase, yet any three-power blocker still kills it clean in the exchange. That pushes it toward being run through unblocked or backed up where the trade is one you want. The standing 0/3 reading is also a quiet enabler for anything that counts power, since in still air this is a zero-power creature that becomes a real clock the instant it moves: a duality most attack-trigger pumpers of its era left on the table, content to be plain undersized beaters rather than blockers that double as threats.