Hexplate Wallbreaker is a rare Artifact — Equipment card from Phyrexia: All Will Be One Commander (ONC), collector number 14. Current market price: $7.45, TCGplayer market prices via Scryfall.
For Mirrodin! (When this Equipment enters, create a 2/2 red Rebel creature token, then attach this to it.) Equipped creature gets +2/+2. Whenever equipped creature attacks, if it's the first combat phase of the turn, untap each attacking creature. After this phase, there is an additional combat phase. Equip {3}{R}