Requires

Gilder Bairn must be on the battlefield. Crystalline Crawler must be on the battlefield. Earthcraft must be on the battlefield. Crystalline Crawler has at least three +1/+1 counters on it. You control at least one basic land. Mana needed: if you control a basic Forest and/or Island, or available otherwise

Steps

1. Activate a basic land by tapping it, adding .
2. Activate Earthcraft by tapping Gilder Bairn, untapping the basic land.
3. Activate the basic land by tapping it, adding .
4. Activate Gilder Bairn by paying and untapping it, doubling each counter on Crystalline Crawler.
5. Activate Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding .
6. Repeat from step 2.
7. Once you have infinite +1/+1 counters on Crystalline Crawler, you may instead double the counters on any other permanent(s).

Results