from UDE's Judge Certification Program (YGO)
Can I use "King of the Swamp" as a fusion substitute for "Superalloy Beast Raptinus"?
King of the Swamp:
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" from your Deck to your hand. The Deck is then shuffled.
http://entertainment.upperdeck.com/COMMUNITY/forums/thread/1547688.aspx
Can I use "King of the Swamp" as a fusion substitute for "Superalloy Beast Raptinus"?
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" from your Deck to your hand. The Deck is then shuffled.
http://entertainment.upperdeck.com/COMMUNITY/forums/thread/1547688.aspx