Marvin, Murderous Mimic, Farmstead Gleaner, and Selvala, Heart of the Wilds

Prerequisites

• Marvin, Murderous Mimic on the battlefield
• Farmstead Gleaner on the battlefield
• Selvala, Heart of the Wilds on the battlefield
• at most available

Steps

1. Activate Marvin using Selvala's ability by paying and tapping it, adding plus an amount of colored mana equal to the greatest power among creatures you control minus 1
2. Activate Marvin using Farmstead Gleaner's ability by paying and untapping it, putting a +1/+1 counter on Marvin
3. Repeat

Results

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