Crackdown Construct, and Basalt Monolith

Prerequisites

• Crackdown Construct on the battlefield
• Basalt Monolith on the battlefield

Steps

1. Activate Basalt Monolith's first ability by tapping it, adding
2. Activate Basalt Monolith's last ability by paying , untapping it
3. Crackdown Construct triggers, gaining +1/+1 until end of turn
4. Repeat

Results

• Infinitely large Crackdown Construct until end of turn