Marvin, Murderous Mimic, Simic Ragworm, and Mona Lisa, Science Geek

Prerequisites

• Marvin, Murderous Mimic on the battlefield
• Simic Ragworm on the battlefield
• Mona Lisa, Science Geek on the battlefield

Steps

1. Activate Marvin using Mona Lisa's ability by tapping it, adding an amount of colored mana equal to Marvin's power
2. Activate Marvin using Simic Ragworm's ability by paying , untapping it
3. Repeat

Results

• Infinite colored mana