Marvin, Murderous Mimic, Farmstead Gleaner, and Doc Samson, Super Psychiatrist

Prerequisites

• Marvin, Murderous Mimic on the battlefield
• Farmstead Gleaner on the battlefield
• Doc Samson, Super Psychiatrist on the battlefield

Steps

1. Activate Marvin using Doc Samson's ability by tapping it, adding an amount of mana equal to Marvin's power
2. Activate Marvin using Farmstead Gleaner's ability by paying and untapping it, putting two +1/+1 counters on Marvin
3. Repeat

Results

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