Gilder Bairn, Crystalline Crawler, and Song of Freyalise

Prerequisites

• Gilder Bairn on the battlefield
• Crystalline Crawler on the battlefield
• Song of Freyalise on the battlefield

Steps

1. Activate Song of Freyalise by tapping Gilder Bairn, adding one mana
2. Activate Gilder Bairn by paying and untapping it, doubling each counter on Crystalline Crawler
3. Activate Crystalline Crawler as many times as necessary by removing counters from it, adding at least two mana
4. Repeat from step 2
5. Once you have infinite counters on Crystalline Crawler, you may instead double the counters on any other permanents

Results

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