Fortress Whale's Oath

Ritual Spell

This card is used to Ritual Summon "Fortress Whale". You must also Tribute monsters from your hand or field whose total Levels equal 7 or more.

Rulings – Yugipedia

Printings:

Tournament Pack 7: TP7-EN011 (Common) - 2005-11-01
Speed Duel: Scars of Battle: SBSC-EN016 (Common) - 2019-08-01
Speed Duel: Streets of Battle City: SBC1-ENC17 (Common) - 2023-08-24

Prices:

Cardmarket: 0.08 €
TCGplayer: $ 0.16