Egyptian God Slime (Quarter Century Secret Rare)

1 Aqua monster + 1 Level 10 WATER monster Must first be either Fusion Summoned, or Special Summoned from your Extra Deck by Tributing 1 Level 10 Aqua monster with 0 ATK. This card can be treated as 1 or 3 Tributes for the Tribute Summon of a monster. Cannot be destroyed by battle. Your opponent's monsters cannot target for attacks, and your opponent cannot target with card effects, any monsters you control, except "Egyptian God Slime".