Marvin, Murderous Mimic, Farmstead Gleaner, and Mona Lisa, Science Geek

Prerequisites

• Marvin, Murderous Mimic on the battlefield
• Farmstead Gleaner 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 Farmstead Gleaner's ability by paying and untapping it, putting a +1/+1 counter on Marvin
3. Repeat

Results

• Infinite +1/+1 counters on a creature
• Infinite colored mana