Horseshoe Crab + Marvin, Murderous Mimic + Transdimensional Bovine

GU identity

Commander legal

The 3 combo pieces

• Horseshoe Crab
• Marvin, Murderous Mimic
• Transdimensional Bovine

How to execute it

1. Activate Marvin using Transdimensional Bovine's ability by tapping it, adding {U}{U}.
2. Activate Marvin using Horseshoe Crab's ability by paying {U}, untapping it.
3. Repeat.

What the combo produces

• Infinite colored mana