Crackdown Construct, Song of Freyalise, and Morphling

Prerequisites

• Crackdown Construct on the battlefield
• Song of Freyalise on the battlefield
• Morphling on the battlefield
• Morphling does not have summoning sickness
• Song of Freyalise has one or two lore counters on it

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