Crackdown Construct, Cryptolith Rite, and Morphling

Prerequisites

• Crackdown Construct on the battlefield
• Cryptolith Rite on the battlefield
• Morphling on the battlefield
• Morphling does not have summoning sickness

Steps

1. Activate Morphling by tapping it, adding
2. Activate Morphling's first ability by paying
3. Crackdown Construct triggers, giving itself +1/+1 until end of turn
4. Resolve the Morphling ability, untapping it
5. Repeat

Results

• Infinitely large Crackdown Construct until end of turn