Marvin, Murderous Mimic, Farmstead Gleaner, and Marwyn, the Nurturer

Prerequisites

• Marvin, Murderous Mimic on the battlefield
• Farmstead Gleaner on the battlefield
• Marwyn, the Nurturer on the battlefield

Steps

1. Activate Marvin using Marwyn's ability by tapping it, adding at least Activate Marvin using Farmstead Gleaner's ability by paying and untapping it, putting a +1/+1 counter on Marvin
2. Repeat

Results

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