Agatha of the Vile Cauldron, Agatha's Soul Cauldron, Crystalline Crawler, and Angry Rabble

Prerequisites

• Agatha of the Vile Cauldron on the battlefield
• Agatha's Soul Cauldron on the battlefield
• Crystalline Crawler on the battlefield
• Angry Rabble in exile

Steps

1. Activate Crystalline Crawler using Angry Rabble's ability by paying , putting two +1/+1 counters on it
2. Activate Crystalline Crawler's first ability by removing a +1/+1 counter from it, adding
3. Repeat

Results

• Infinite colored mana
• Infinitely large creatures until end of turn
• Infinite +1/+1 counters on creatures you control that have a +1/+1 counter on them