Marvin, Murderous Mimic, Horseshoe Crab, and Sage of the Maze

Prerequisites

• Marvin, Murderous Mimic on the battlefield
• Horseshoe Crab on the battlefield
• Sage of the Maze on the battlefield
• Marvin does not have summoning sickness

Steps

1. Activate Marvin using Sage of the Maze's ability by tapping it, adding
2. Activate Marvin using Horseshoe Crab's ability by paying , untapping it
3. Repeat

Results

• Infinite colored mana