Goldwarden's Helm is a common Artifact — Equipment card from Phyrexia: All Will Be One (ONE), collector number 13. Current market price: $0.20 (foil $0.25), 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 +0/+1. Equip {1}{W} ({1}{W}: Attach to target creature you control. Equip only as a sorcery.)