Helm of Kaldra is a rare Legendary Artifact — Equipment card from Fifth Dawn (5DN), collector number 131. Current market price: $3.92 (foil $16.11), TCGplayer market prices via Scryfall.
Equipped creature has first strike, trample, and haste. {1}: If you control Equipment named Helm of Kaldra, Sword of Kaldra, and Shield of Kaldra, create Kaldra, a legendary 4/4 colorless Avatar creature token. Attach those Equipment to it. Equip {2}