Jegantha, the Wellspring, Necrotic Ooze, and Morphling

Prerequisites

• Jegantha, the Wellspring in the graveyard
• Necrotic Ooze on the battlefield
• Morphling in the graveyard

Steps

1. Activate Necrotic Ooze using Jegantha's ability by tapping it, adding that cannot be spent to pay generic mana costs
2. Activate Necrotic Ooze using Morphling's first ability by paying , untapping Necrotic Ooze
3. Repeat

Results

• Infinite black mana that cannot be spent to pay generic mana costs
• Infinite green mana that cannot be spent to pay generic mana costs
• Infinite red mana that cannot be spent to pay generic mana costs
• Infinite white mana that cannot be spent to pay generic mana costs