Tromell, Seymour's Butler, Crystalline Crawler, and Crab Umbra

Prerequisites

• Tromell, Seymour's Butler on the battlefield
• Crystalline Crawler on the battlefield
• Crab Umbra on the battlefield
• available

Steps

1. Activate Tromell by paying and tapping it, causing you to put at least five +1/+1 counters on Crystalline Crawler Activate Crystalline Crawler five times by removing five +1/+1 counters from it, adding
2. Activate Crab Umbra by paying , untapping Tromell
3. Repeat

Results

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