Artefato — Equipamento
Quando Martelo de Pistão entrar no campo de batalha, anexe-o à criatura alvo que você controla.
A criatura equipada recebe +3/+1.
Equipar — Sacrifique um artefato.
You can sacrifice Piston Sledge to pay its own equip cost. It won't become attached as it will be in your graveyard.
If there are no creatures on the battlefield that Piston Sledge could be attached to when its "enters" triggered ability resolves, it remains on the battlefield unattached.