Kaiba Corporation Secret Rare (海馬コーポレイションシークレットレア Kaiba Kōporeishon Shīkuretto Rea), is an OCG-exclusive rarity whose icon appeared on the Yugioh-Card.com official card database; the rarity has not appeared on any physical cards.
The cards would be similar to Secret Rares (a rainbow holofoil name and a parallel holofoil image), but would also have a Kaiba Corporation Rare coating.