King of the Swamp (DR2-EN195) - Dark Revelation Volume 2 Unlimited

You can substitute this card for any 1 Fusion-Material Monster. When you do this, the other Fusion-Material Monster(s) must be the correct one(s). Discard this card from your hand to the Graveyard to add a Polymerization Spell Card from your Deck to your hand. The Deck is then shuffled.